No, really. Write anything.note Disclaimer: Not all objects are available. TV Tropes is not responsible for an object not being summoned while attempting this trope. Results may vary.
(Sheldon is learning to drive with a custom-made simulator) Leonard: How did you manage to get on the second floor of the Glendale Galleria? Sheldon: I don't know, I was on the Pasadena Freeway, missed my exit, flew off the overpass and... one thing led to another.
Some games keep a tight rein on the player's capacities. Others never realise in time the full scope of the Combinatorial Explosion and break like a fragile twig the first time a creative player gets a grip on them. Only a brave few dare try and respond wittily and internally-consistently to absolutely everything a player could try.
The point at which we can say the Dev Team Thinks of Everything is when there are strange circumstances, tricks, combos, Sequence Breakers, etc. and not only has the Developer (Dev) team anticipated them, but they put in special content just in case. Stopping players from Sequence Breaking with Invisible Walls, convenient blockades, a guard NPC that doesn't let you pass, etc., for instance, doesn't qualify because even though they anticipated you would try this, they didn't exactly give you special content for trying. On the other hand, if entering the castle you weren't supposed to reach yet awards you a brand new cutscene where you are told "Congratulations, you have broken the game's script! Now back to where you belong!", that DOES qualify. It also doesn't count as this trope if the content is set up in such a way that they are clearly baiting you to try this, such as leaving a severed head lying on the ground and a basketball hoop nearby. It might count, however, if they let you carry the severed head and there is a basketball court several levels later. It definitely counts if you have to do the obvious trick without the game containing a throw mechanic. Similarly, content that is merely hidden wouldn't be this trope either - that's just an Easter Egg, Secret Level, etc.
To truly qualify, however, this shouldn't just happen in one or two occasions in the game, but instead happen so often that you really would think "the Dev team thinks of EVERYTHING." The term was coined by the NetHack community, due to the game's open-source design and long turnover between versions encouraging the proliferation of Easter Eggs — maybe half the game's source code, by weight. See also Crazy-Prepared, Artificial Brilliance, and Genius Programming. Compare The Producer Thinks of Everything, where the creators of a TV show seem to have planned out very, very far ahead.
Metroid Fusion has the notorious shinespark Sequence Breakcutscene, viewable here. This was an unexpectedly difficult task for a Nintendo game. The game itself acknowledges this, praising the player for their high skill, and actually wondering how many players would see the cutscene. There's also a slight second scene that plays if you talk to your AI CO right after he dismisses you.
It should be noted though that this message is actually possible to reach without needing to do the ridiculously fidgety Shinepark trick. The developers obviously didn't think that anyone could hit the puffers just before the Diffusion missiles with regular ice missiles without them puffing up. You can.
Metroid Prime 3 also has a Timed Mission in which a meteor is about to crash into the planet, and at one point you catch a glimpse of it as you move through an outdoor area. If you stay put and watch the meteor instead of moving on, it will slowly move through the sky, speeding up in the last 10 seconds or so as it crashes towards the ground. Made better by the fact that you are only warned about the time until impact via the in-game public address system, with no onscreen countdown, so players may think the warnings are triggered by Event Flags and not realize the mission is actually timed and watch the meteor just to see what, if anything, happens to it.
In Metroid Prime, if a regular or Fission Metroid drains enough of your energy, it will explode. The developers put a lot of thought into how Samus' suit works; those symbols for changing beams are the hand gestures she needs to make, as verified when the player has the X-Ray Visor on. If Samus is hit and throws up her hands with said Visor, the player can see the bones in her arm. With the thermal visor, the Ice Beam and Plasma Beam are visibly cold and hot. If a bright light flashes near Samus, the player can briefly see the reflection of her eyes on the inside of her visor, complete with blinking and looking around. And so on.
It's also possible they accounted for Sequence Breaking since Thardus, the boss of Phendrana Drifts, is extremely weak to the Plasma Beam, a weapon you shouldn't even have until quite a bit later.
In the same vein of accounting for Sequence Breaking, Metroid Prime 3 has an instance where a mini-boss on Bryyo actually has a weak spot that can be exploited with the Nova Beam and the X-Ray Visor... items that the player can't normally get until near the end of the game.
In Okami, near the beginning of the game, you are to pick up Susano from his hut, and carry him a short distance to destroy a boulder. However, all of the villagers in the city have something to comment (usually of how Susano should be training instead of messing around with a dog), and even dragging him to the Shrine of Nagi nets you a special comment.
For that matter, you can do lots of random things with your brush before you get certain brushstrokes (usually limited to creating flowers or such, but it also changes the more previous brushstrokes you have).
If you try to call the sun before you reach the high point of the village, Issun will ask what you're trying to accomplish by drawing a circle in the sky. Later, after you've "learned" the technique, he'll reference your earlier attempt and ask if you're withholding any other techniques.
A segment near the end of Cave Story has your character briefly wear a Mimiga mask to infiltrate the Plantation. Although he traded his jetpack for it, he can still go around, complete a certain sidequest and even finish the game without trading the mask back, changing pretty much all the Non Player Characters' reaction to his appearance.
If you have Mr. Little when you get to the ending (either normal or true), he'll ask if you're forgetting something, as you just separated him from his family.
Apparently, Nintendo thinks that players can get lost in The Legend of Zelda: The Wind Waker's gigantic overworld, because the game automatically turns Link around if he is in his boat. However, this can be bypassed by swimming with cheats that allow Link to swim indefinitely. But just when you think you defeated the programmers, Link drowns anyway. With cheats. In a place no one, during normal gameplay, can get to anyway. Nintendo programmed the game to automatically stop anyone from passing too far out of the world even with cheating devices, which Nintendo, or any other company, for that matter, never try to circumvent in other games.
Navi might be annoying to all players of The Legend Of Zelda The Ocarina Of Time, but give the creators credit. If you forget where you're supposed to go, just stand still for a minute and Navi will remind you...
The Great Deku Tree wanted us to go to visit the princess at Hyrule Castle....Shouldn't we get going?
An arctic wind is blowing from Zora's River...do you feel it?
What would Saria say if we told her we're going to save Hyrule?
And so forth.
A minor example in the NES Rambo game, which was based on Rambo: First Blood Part II: a significant character is mortally wounded and dies during an in-game conversation, which mirrors the events of the movie. That character then (logically) never appears again in the game. The conversation, however, is optional; the developers anticipated players skipping the conversation and the character will appear later (including in the ending) with new dialogue if that fatal conversation is skipped, allowing the character to be Spared by the Adaptation.
In Resident Evil 4, you will spot a group of villagers at the end of the very first area, shortly before entering the village. They are on the other side of a river, and since your handgun - the only weapon you have at this point - has insufficient range, you cannot kill them. If you start a New Game Plus, however, these Ganados are now gone because you most likely have a long-range weapon like a sniper rifle or rocket launcher that could kill them.
Action Game
In Batman Arkham Asylum, if in solving one of the Joker's puzzles you don't do things in the order you're expected to — for example, taking off a ventilation duct grate before moving towards the stairs to make your job easier — the Joker will lampshade it, saying something like "Reading the last page first? That's almost cheating!"
Better yet, during the third Scarecrow scene, you're presented with a cutscene. Where you can normally press A to bring up a message reading "Skip: B" in the corner, allowing you to skip it, since you're temporarily playing as the Joker, the message reads "Skip: J". Glorious stuff.
In Dead Rising, "Queens" are wasps that, when crushed, cause the heads of nearby zombies to explode. (It Makes Sense in Context.) You can capture them in jars, and throw them on the ground to smash them and unleash their effect. Of course, since the only requirement is to crush the queen, in Dead Rising 2 you can also set off the queen by dropping the jar on the ground, and then shooting it. This is a legitimate tactic for Batmanning your way through a tricky scenario, as your inventory slots are severely limited.
Adventure Game
If you play through Journey without a companion and then one joins you later, the mural that you see at the end of chapter six will only show one red-cloaked person until it pans to the level where your friend joined, when two will show from there until the endgame. The reverse is also true — if you lose your partner in the temple (for instance, they go back down for bonuses and you don't), the mural will show you partnered for the sections where you were together... and facing the winds alone at the end.
In the third Myst game, Exile, you have to force Saavedro to give you the Releeshan book in exchange for letting him go home. Once he gives it to you, you're supposed to lower the inner crystal so Saavedro can leave... but you don't have to. You have the option of leaving Saavedro trapped between the outer crystal and inner crystal and going straight back to Atrus. If you do, Atrus calls you out on it.
Full Throttle gave you a boxful of mechanical bunnies intended for clearing a path through a minefield. If you had any left over later, you could chop them up for fun with the help of a large truck's engine fan.
Left over? You can go back to the shop after a certain point and gank a second box of the things! In fact, "Ride of the Valkyries" is playing while you do it.
There is also a scene where you're attempting to operate the computer console of an out of control jumbo-jet screaming down the highway (It Makes Sense in Context). Most options lead to "Computer damaged, unable to comply." If you try to select "Access Adult Movies", the screen begins to flash "Loading..." before hitting you again with the error message. Bastards.
The Quest for Glory series had a ton of these, especially amusing for players who think of particularly creative ways to get themselves killed. If you play as a thief, you start out with a lock pick in your inventory. If you type "pick nose", the hero will stick the lock pick up his nose and die, and you will get a game over. However, if your lock-picking skill is high enough, you will get a message that says, "Success! Your nose is now open!". Later games have the game reply "Success!" with the same sound effect the player hears when picking a lock. This also increases your lock picking skill.
The games also provided a lot of random, snarky descriptions for mundane objects that the player could examine.
While Quest For Glory IV was an Obvious Beta on the programming side, the writing department was clearly not slouching. Among other things, every single item in the game has its own message when you try to use it on yourself instead of a generic "that does not work" message. For example, trying to use a wooden stake meant for vampire slaying on yourself will cause the narrator to berate you for mixing up "stake" and "steak".
If you type "put down lamp" instead of "use lamp" in Quest for Glory II, it uses the colloquial meaning of "put down" and shows your character insulting the lamp before placing it on the ground.
The variation "drop lamp" will result in you breaking up with the lamp before you place it on the ground. You heartbreaker, you.
Even their later point & click adventures have this aspect. Kings Quest VI has Alexander Breaking the Fourth Wall to yell at the player if they made him fall repeatedly during one sequence (if he wasn't killed by said fall).
In the Hitchiker's Guide To The Galaxy text adventure, it is necessary to the plot at one point to "enjoy Vogon poetry". Earlier, you can "enjoy mud" (it's nice and squishy!), but if you try enjoying Ford, you are sternly told that this isn't that type of game. Additional fun can be had by inputting random words into the Guide — it has entries on some very unlikely things.
Often the game will refer you to a footnote (Like SEE FOOTNOTE 9), and when you type "footnote 9" it tells you something. If you keep on going through the footnotes (Trying footnote 10, 11, 12, etc) eventually you get a string of "There is no footnote (number)", until you finally get "It's fun reading all the footnotes, isn't it?"
Leisure Suit Larry in the Land of the Lounge Lizards, being the first Sierra game to be publicly playtested, included a wide variety of possible inputs to any situation, often with comedic responses: During playtesting, the developers would take note of various phrases used by players in certain situations, and think of new ways for the game to react to it. For a particularly amusing example, typing the command "masturbate" at any time would result in the prompt "The whole idea was to stop doing that, Larry!"
In Grim Fandango, you can use the "Pick Up" command on several NPCs and have it be interpreted as an attempt to, well, pick them up. For example, when the command is used on a female former co-worker, Manny replies "I guess I could, now that we're not working together."
Similarly, if you try to "Use" your abusive crew in the first Monkey Island, Guybrush will say "They're not the only ones being used around here." There's also a scene where you can click on the sun with your default "walk to" command equipped, and Guybrush will remark "Oh, sure. Walk to the sun."
Monkey Island also has a few "pick up" jokes like the one above. In The Curse Of Monkey Island you can try it on Griswold and Guybrush says "I don't indiscriminately pick up bartenders." And several with Captain Kate in LeChuck's Revenge.
In Space Quest 4, there is a one-in-a-million chance that any given player will figure out how to pick up the bunny in the first part of the game, and then while being shot at later pull out the bunny and use it on the shooting mook. This has not only a response, it has a voiceover reading it: "Don't throw the bunny at the Sequel Policeman! He might have a hare-trigger!"
At one point, you end up having to delete some files from a computer. One of the files is named SQ4. If you delete it, the game simply quits.
In the second game, there is a spike pit in the first jungle scene, hidden under a false sod. If you try to LOOK AT TRAP, the game will berate you for being paranoid. It will only do this in the screen with said trap.
In Star Trek: The Kobayashi Alternative, a text adventure, typing in swear words gets the NPC's to react with shock, and typing them in three times in a row causes McCoy to cart you off to Sickbay for a Non-Standard Game Over (since you've obviously gone insane, poor soul).
Zork responds to commands such as "win" and "die", and characters react to the phrase "Hello, Sailor".
In Zork II, at one point you come across a room containing naught but a giant bucket. If you should type "kick bucket" while trying to Get Ye Flask, the parser helpfully replies, "Kick the bucket? OK, if you insist. *** You have died ***"
"Eat", 'Eat what?', "Eat Self", 'auto-cannibalism is not the answer'
"Count Blessings" results in "Well, you're playing Zork, for one..."
The Scott Adams text adventure game Pirates Cove features a door that won't open. If you type in "BREAK DOOR", the game will respond "Sorry, I don't feel destructive today." Type in "FEEL DESTRUCTIVE", and it will respond with something like "OK, I'll destroy your game!" and give you a game over.
Riven has unique game-over cutscenes for everything you can possibly think of doing. If you trap yourself in the prison book on any of the main islands, you get a game-over cutscene with Gehn — but if you trap yourself in the prison book while in the Moiety world, you get a completely different one. The same is true for game-over cutscenes you get when releasing Gehn from the prison book. In fact, there's even a unique game-over cutscene that you can only reach if you play through two-thirds of the game to get a secret code, then open a saved game from the very beginning and use the code long before you could possibly have known it! This is even more impressive when you consider that the code is different each time you play — so you can't reach this cutscene merely by using the code in a new game. It has to be one of your months-old saved games. This grand tradition is continued with Myst III: Exile, which also has an impressive number of very-slightly-different-from-each-other Game Overs, some of which are very difficult to reach though one can be reached in normal game play.
Beyond Zork had this back in the 1980's, ending the game if you restored from a save file with an improper checksum "Shame on you."
The old text adventure Time Quest involves quite a bit of time traveling. Usually, leaving items in one time period doesn't change anything in other periods, but in one particular time period, you can leave an item in a cache in the past and then pick it up in the future (or, more recent past). If you do this, then go back in time, you can have two items of the same type (the original, and the one you got from the future). But try to leave the "copy" in the cache (so you can go forwards and get another one), and the game stops you: "Now I'm about to put up a timestream paradox message, but because you deserve a bonus for your ingenuity I'm going to bump your score by 5 points that no one else will get". Don't get too greedy, because if you don't fix the situation, it's game over time!
The entire point of the interactive fiction Pick Up The Phone Booth And Aisle. Just start with the title alone, and try flying, swimming, or some infamous IF buzzwords, really, anything, and see the results. PUTPBAA is a combination of two earlier games with a similar concept: the author's own Pick Up the Phone Booth and Die, and Aisle. The latter game takes place in the middle of a grocery store, and only lasts a single turn. The player can use this window of time to perform such psychotic actions as climbing the grocery shelves, or stripping naked.
This is fairly common in "one-room" Interactive Fiction stories. When the author only has to focus on a single player location and the items within, more effort gets to go to verbose item descriptions, verb creation, and clever responses to unique entries.
Seen somewhat in the second Journeyman Project game and especially in the third with regards to commentary by your in-game companion.
The most notable example occurs in Shangi-La when the player needs to place a specific item in the open hand of a Buddha statue. The reasoning involved for what item needs to go there is only apparent if the player has first talked with the spiritual leader of the monastery to learn of the symbolism involved. If the player places the correct item without the information, your companion stutters in shock before asking if you've been reading the guide.
There are also instances where the player is in danger of being injured if they attempt to directly pass through an obstacle. However, they are free to attempt this several times, to varied comments from your companion.
Different disguises in the third game get different reactions from other characters. Amusingly enough, it's possible to get yourself knocked physically assaulted by two people if you use the correct disguises... and this happens in the Buddhist monastery.
The games Ben There, Dan That!! and its sequel Time, Gentlemen, Please! as a point-and-click adventure have unique responses for almost every combination of object, action and place you can imagine. Hilarity Ensues.
The debug version of text adventure games by Andrew Plotkin are well known for having hilarious messages appear if bugs leave the game in discogruent situations. Examples include: "You are seeing afterimages of afterimages. Your eyes explode." and "You fail to answer a question that has not been asked. How Zen."
The final Ben Jordan game has this. If you try to use the hand icon on people to touch them, occasionally the game will just get flat-out snarky and say "Shouldn't you apply for a job with the TSA?" or "Who are you? Hercrabbiness?" however, if you use the hand icon on a priest, it says, "Shouldn't it be the other way around?"
Beat Em Up
In the Spider-ManPS1 games, if you attempt to enter certain adult words into the cheat code screen, Spidey will swing by and punch the offending letters away to replace them with something more wholesome, like "kittens".
In the first boss fight with Venom, Venom actually has uniquely recorded lines for if you somehow manage to get out of his line of sight.
In Teenage Mutant Ninja Turtles 2: Battle Nexus, you at one point fight The Shredder in Feudal Japan in a simulation, and fight him in an area full of bamboo gates on a cliff. The gates actually can be broken, and is required for finding a bonus, and on that note, you can actually just skip the trouble of whittling The Feudal Shredder's health down to zero and just knock him off the cliff, instantly winning the boss fight, along with loosely replicating the method in which he was defeated in the actual show.
Driving Game
In Wangan Midnight Maximum Tune 2, 3, and 3 DX, after you clear all 80 stages of Story Mode (or 100 stages in the case of Maximum Tune 3 DX), you get a title, and can do all of Story Mode again, as many times as you want. Subsequent Story Mode clears will net more titles, and the titles keep coming out. 3 DX, for instance:
If you time out a stage in Story Mode (very unlikely given the extremely lenient time limit), you get the title "Fight."
The cars in "Forza Motorsport 4", feature actual working dashboards. Besides the obvious meters and gauges like the Speedometer and Tachometer. All the cars have accurate Odometers and older classic cars have added mileage. The cars with clocks also read the time the Xbox 360 has.
Unfortunately, however, the dashboard speedometer will always display your speed in MPH even if you've selected metric units in the options and are driving, for example, a German car on a German track (Germany, like most European countries, uses km/h, i.e. kilometers per hour).
The game also renders tire wear realistically based on suspension settings and the race track being driven on.
Shift 2: Unleashed does the same thing with monitoring oil pressure and oil temperature like most cars have.
In Sonic & All-Stars Racing Transformed, the announcer will scold you if you turn him down in the audio options. But if you turn him up, he'll praise you instead.
Edutainment Game
Oregon Trail 2 actually programmed in the snowstorm that trapped The Donner Party if you head to California in the right year, and take the same passage they did.
Pinball Science, by the creator of The Way Things Work, required you to Enter Solution Here in order to answer quiz questions. If you typed the right answer but spelled it incorrectly, the game responded differently than if you simply typed the wrong answer.
Fighting Game
In the Dead or Alive games, namely Dead or Alive 3 and both Xtreme games, Kasumi (or in the case of the Xtreme series, all of the characters) can be hacked to be rendered fully nude. In that case, they are given pubic hair, nipples, and vulvas, pretty much making them anatomically correct.
On a related note, in Xtreme Beach Volleyball, there is a glitch that occurs if the player gives the girls translucent visors that makes their clothes disappear (which is also the closest thing to a legitimate nude mode in the game). The creators apparently anticipated this and added in colored stars and blotches on the private areas (the nipples and the pubic/vulva area, respectively) so as to keep it relatively tasteful.
Also, if the player wears a bathing suit long enough in Xtreme 2, they'll develop tanlines.
To pause the game in Skullgirls you have to hold down the start button. While this seems unintuitive at first, it starts to make sense when you consider that pausing the game mid match in a tournament is usually grounds for a disqualification alongside being downright rude. Depending on the controller, it's also possible for your finger to slip off the face buttons in the middle of a hectic match and hit it by accident.
Skullgirls also has Idiosyncratic Combo Levels that go up to 999. While they don't cover EVERY combo between 2 and 999 hits, there are some sneaky ones (such as 403 hits generating a "Forbidden" tag, referencing the web server error of the same code).
In Dissidia 012 Final Fantasy, when playing against Sephiroth with Aerith as a summon, the player might be tempted to attempt to use Aerith to use Holy against Sephiroth. Sephiroth is scripted to respond by homing in on Aerith and attacking her with Hell's Gate, emulating the scene in Final Fantasy VII where his kills Aerith (while she's trying to cast Holy) in the same way. Similarly, alternate dialogue can be accessed by Exdeath if the player decided to use his EX Burst against Gilgamesh, which is based on his exchange when banishing the latter to the Void in Final Fantasy V.
Also, if the player manages to play as Terra during the Moogle sidequest in the original game, the cutscene where the player discovers the moogle is extended to have Terra becoming infatuated, rush up to the Moogle, and cuddle with it with her face and arms, and additional dialogue is added in where the Moogle will tell Terra to "lay off on the fur-ruffling."
During their second livestream of the My Little Pony fangame Fighting is Magic, Mane6 anticipated that the viewers would want to see some footage of Fluttershy. However, Fluttershy wasn't complete enough to be showcased, so as a joke they showed gameplay of her, but she was invincible and only had a One-Hit Kill attack.
SmackDown vs. Raw allows you to download Creator's PetMichael Cole. Do so and he will be pushed to the moon, title match after title match after title match, main event after main event after main event, change the card and Cole will just be in the next one. The game goes out of its way to make him The Scrappy.
First Person Shooter
Operation Flashpoint: Especially in the Game Of The Year edition. Confined only by the limits of the island you're on and the abilities of a normal human soldier, you can do anything, literally. You can choose which side you want to fight for, you can disobey orders, leave the mission area (although on rare occasions this will result in a failed mission), you can steal vehicles, both civilian and military (civvie tractors are found abundantly in missions and hence are a very good way to get around; which is something most players don't think of), instead of destroying a target with a bomb you can capture an enemy tank and use it to blow shit up, and inversely, if you're on a tank mission, you can leave your tank and enter combat on foot, while still commanding the tank via radio. This is a good way to provide support while fighting soldiers with anti-tank weapons. If you have other soldiers under your command, you can order them to do anything, too.
The Nameless Mod has this all over the place, mostly because as a mod for a nearly 9 year old game, they know all the exploits in the engine. For example: climbing over a fence before you can unlock it will result in an NPC on the other side asking how you got there, and listing some of the possible methods, such as grenade climbing (sticking a grenade to the wall, jumping on it, sticking another to the wall, jumping, removing the first, and repeating).
Extra Mario Bros, a ROM hack of the original Super Mario Bros., has this as well. The original SMB engine is full of bugs, but in the hack, there's no way to get stuck. Ever. And there's plenty of out-of-the-way secrets that require you to use these bugs to get to otherwise inaccessible areas.
In The Nameless Mod there is an area that you will only be given password information needed to enter if you ally with one faction. If you remember the password and use it to enter while aligned with the other faction you will receive special messages commenting on your entry and giving a little information about the area.
Not only that, if you break the game's plot by doing something like killing a plot-important NPC (who are normally protected by armies of goons and robot turrets), the game will actually call you out on it (in the form of a large talking logo of the modder group, no less), and ask you why you felt it was a good idea to try to break the game, with answers ranging from in-game justified reasons to "It seemed like fun". The logo will then kill you for breaking the game. You're gonna kill me, just because some developer didn't know how to set bInvincible=True?!
Rise of the Triad uses "pushwalls" for hiding secret areas. A pushwall reacts to the "open door" command and moves forward until it hits another wall (if you've played the original Wolfenstein 3D you've seen these). If it hits the edge of the map, the game crashes with the error message "Pushwall tried to escape at (map coordinates)." One of the playtesters, who was also a graphic artist for the game, thought this was hilarious and immediately drew a picture of a brick wall running off the map declaring, "I'M FREEEEEEEE!◊" This picture was actually used in-game for the aforementioned error message.
The same incident resulted in the warp-only level "This Causes an Error!", which does exactly that and is where most people discovered this.
In System Shock 2, if you bring a basketball to the basketball court - which you would've had to bring with you from the start of the game - and take the time to score a point (which can be very difficult for the lack of a throw skill), you are rewarded with an Easter Egg audio log from the ship's monkeys saying that they stole all the ship's bananas.
Left 4 Dead 2 does this with some of the achievements that require actions from one player to do on another, like Heartwarmer and Shock Jock. You can't kill a player and revive them hoping to advance on the Shock Jock achievement for example. A zombie has to kill the player in order for you to advance in the achievement.
The zombies in both games are attracted to loud noises. The Dark Carnival finale shows that loud music (and fireworks) suffice, which also works in other campaigns: a Horde is summoned when the song "Re: Your Brains" is played for long enough on one of the in-game jukeboxes, due to the chorus sounding like a horde was alerted, thus alerting a horde to the players.
Also in the sequel, Valve put in a check for cheating in Survival mode. If players manage to get to an area where they are not supposed to be in order to avoid the zombies and make the game never ending, the AI Director will generate a Spitter's acid patch on the players to force them to get back into the playing field. If the players somehow are able to avoid this, the director will then just outright damage the players continuously until they die or get back in their proper place. This check is not foolproof since there are a few places players can camp up where the director thinks the players are not cheating.
Two finales in Left 4 Dead 2 are triggered by riding down in an elevator. However, due to the buggy Source engine and/or lag online, sometimes the finales in The Passing and Dead Center never start, even though you are in the general finale area. Normally, this would make the game Unwinnable, but Valve made a back up trigger where a nearby object will glow blue to indicate that you can "use" the object. Doing so triggers the finale as normal.
In the first map of The Sacrifice campaign, there's a wrecked train car with a Tank inside. There is no other way around so you have to free the Tank to proceed. Most players will fight the Tank and the accompanying horde before moving on, but there are some players that will try to outwit the Tank by baiting it far away and then bolting to the train car and opening the 2nd door inside to proceed. Valve thought ahead and made it where the door does not open until the Tank is killed.
In the first map, Dead Centre, the survivors introduce themselves in an elevator. If one (or more) of the team is dead, another person will introduce them instead.
Coach: "Who'd we lose?"
Nick: "I think she said her name was Rochelle."
In Half-Life and Half-Life 2, many out-of-the-way areas can be reached by inventive or simply persistent players. The developers tend to place useful or rare items here, or if it's outside the way, block them with invisible, selective brushes.
In Half-Life 2: Episode 2, it is possible to reach an otherwise inaccessible cave through the antlion guardian's powerful headbutt attack. There is a small message saying "How did you get here??". Besides, carrying a garden gnome all the way through the game and sending it to space with the rocket in the finale will trigger an achievement.
In Half-Life 2, near the end of the Water Hazard chapter, there are a few sealed-off pipes with toxic waste in them. One of them has an entrance that can only just be reached. Although it may just appear to be a generic hazard, keep going and turn left and you'll find a secret cave with a Vortigaunt roasting a Fast Headcrab on a spit. Prompt him with the 'use' key and he'll say every line spoken by Vortigaunts in the game, and a few which were recorded specifically for him.
There's now an achievement for finding this guy.
If a necessary NPC or vehicle is killed or destroyed, a special message appears listing the player's name, status, and reason for failure, ending the game. If the reason is getting stuck, the reason will be "Demonstration of exceedingly poor judgment."
This also occurs if one jumps off certain parts of the highway in Highway 17.
For two chapters in Half-Life 2, Gordon is accompanied by small groups of La Résistance, who make various comments as appropriate to the situation (or not...). If you happen to die with the crowbar equipped, one of them will shout "Dibs on his crowbar!"
In the 1998 first-person shooter SiN, the developers planned for players who wanted to break out of the confines of certain levels. There is one level where the main character of the game (a police officer) must swim through an underwater passage, complete with currents that try to push you onto a certain path. If you are somehow able to swim against these currents enough (something most players won't try anyway), you'll access a secret room that's full of submarines, with a message telling you that you're not supposed to be there, and that you need to start playing the game again.
In one of the later levels, you'll visit the main villain's (Elexis Sinclaire) estate, where she's planning her takeover of the world. There's a secret janitor's closet you can access that will let you watch live video of her making strange sounds as she sits in a jacuzzi (with a view from the wall behind her) that will be seen in the next level. However, if you use a cheat code to clip out of the level, you'll find that said jacuzzi area early, and you'll subsequently realize that the developers put a special animation of the bikini-clad Sinclaire having A Date with Rosie Palms, for players who who took the time to cheat.
In Team Fortress 2, the Dead Ringer unlockable for the Spy — an invisibility watch that only activates when the player is being attacked and leaves a fake corpse and dropped weapon on the ground as if he has been killed — also generates a fake kill message in the HUD and even counts the fake kill towards any relevant achievements.
In 2012, they added a miscellaneous item for the Scout, Spy, Heavy, Engineer, and Sniper called the Triad Trinket, which is an open-shirt with a gold necklace that also adds a flipped up collar. The "Bear" style adds chest hair, but this has no effect on the Scout, the youngest mercenary of the team.
This may just apply to Source engine games in general, but refreshing the server browser usually causes the servers to load out of order before being rearranged to properly match the player's sort setting. If the player attempts to double-click on a server in the split second before the servers re-sort, and the second click lands on the wrong one, the game will interpret this as a successful double-click on the correct one anyway and connects to that server.
During Mann Vs. Machine, you have unlimited setup time until someone says they are ready. When a wave has a Tank, Demomen often set up a bunch of Crit-boosted sticky bombs, either from a canteen crit-boost or a Medic using the Kritzkrieg. If you try to use the setup time to have someone change to Medic, boost the Demoman so he can lay the stickies, then change back and play as a different class, the stickies will disappear.
The Halo series. It's Bungie, what did you expect?
In Halo 3, you can exploit a glitch to keep Sergeant Johnson alive, even though he's killed mid-cutscene. With this glitch activated, he is then able to be killed, and taken over by a flood form. Amusingly, he will note "Ain't I immune to this!?" while it happens. And it's true; gameplay- and story-wise, he is supposed to be completely immune, meaning Bungie prepared for the possibility you would somehow glitch the game and get him infected.
In said game, try turning the elephant upside down. When you go to flip it back up, the game says, "Press L1 to... Wait, WHAT? How did you do that?"
In Halo Reach, since your Spartan is customizable for campaign as well as multiplayer, the helmet at the beginning and end of the game is the helmet your Spartan wears. Yet the inside of your helmet, which is briefly seen in the opening cinematic, matches the default helmet regardless of which helmet you might have selected.
When you first get the Jetpack, you can actually bypass having to use the elevator to get to the top of the building. You can use the Jetpack to get to a point where you can hijack in midair one of the ambient Banshees and fly to the top, saving yourself a whole lot of hurt and ammo.
Most of the series' multiplayer maps have passive storytelling & atmospheric details strewn all over them, should you wish to look around them in a custom game (or Forge in Halo 3 onwards, which is better as it allows you to fly). Some of the best examples include Assembly and Orbital (from Halo 3) and Solitary (from Halo: Combat Evolved Anniversary). Some of Halo 3's maps are also linked, if you look (Citadel and Epitaph are set in the same building, while the star closely visible out of the windows of spaceship-set Heretic is in fact the sun of Sandbox, suggesting that is where the Covenant fleet is headed). It's quite remarkable that Bungie have put so much effort into things most fans won't even notice or begin to look for.
The final boss of Doom 2 is essentially a Hellmouth, just a giant face taking up an entire wall, spewing baddies from its forehead that you have to carefully aim a rocket into from a rising platform. As easy as it would have been just to make it a textured Weak Point, a noclip code lets you run straight into the thing and down a tunnel, at the end of which you find the true target: John Romero's head on a spike! This is even reflected in the sound effects; the Hellmouth makes what sounds like your average eldritch groan, but if played backwards, it says, "To win the game, you must kill me, John Romero!"
In Quake II there is a point where you encounter the huge “lid” of an underground rocket launch tube. It is too high to reach normally, but if you rocket-jump to the top, there's some ammo, and a message saying “You crazy rocket-jumpers!” appears.
It is theoretically impossible to hurt yourself with the Lightning Gun in 2004 by virtue of the weapon being Hit Scan. However, if you somehow manage to do it anyway, there's a specific death message for that occurrence:
<Player> violated the laws of space-time and sniped himself.
Other Hit Scan weapons usually have similar messages. It's possible to see them in some games due to a self-cloning glitch. Using the same method, you can Tele Frag yourself; this gives the message:
<Player> tried to go where no man has gone before.
The first (and so far, only) level of the Prey mod Altered Reality has a section in a sewer that does not go anywhere and cannot be reached except by noclipping. Not only does that section contain a hidden message, written on a wall, that says "You're not supposed to be here", but if you noclip into said section and then deactivate noclipping mode, Tommy will actually read the message and make a comment about it.
One of the missions in Red Faction has you infiltrating an Ultor office. At one point, a guard stands in the way of your objectives. One of the ways you can dispatch him without raising the alarm is to enter the women's bathroom nearby; he will follow you in, because you are a man.
A guard also has a wry comment if you jump in the fountain.
Mascot Fighter
Super Smash Bros has the audience. The audience existed in the first game, where it would applaud in a few situations, and gasp when a character manages to recover from a powerful attack. It got fleshed out more in Melee, with cheers for each character and a few other responses. This trope truly gets invoked in Brawl, however. The audience has a wide variety of reactions to thousands of events; if it seems like they should be gasping, or applauding, or whatever, they already are.
Also in "Brawl", if Kirby eats a Golden Hammer, he can determine if it was a Squeaky or not. If it was a Golden Squeaky Hammer, it makes a slight squeak sound when he eats it.
Case in point: if in Stock Mode you lose your last life, and then some time later a leftover attack of yours kills an opponent (most often seen with the Motion Sensor Bomb), then the audience will cheer your name even though you've lost.
In Super Smash Bros Melee, each player is awarded bonuses after a match based on his or her performance. These bonuses range from easy (Coward: frequently run away from opponents) to extremely challenging (Switzerland: never attack, never take damage) to why-would-we-even-do-that baffling (Button Holder: hold down one of the attack buttons for the entire match). In short, no matter how you play the game, you'll be recognized for it. If you're trying to get the Diskun trophy, you're gonna have to to get every single one of these bonuses; in other words, you'll have to think of everything that the developers have thought of.
Mecha Game
Mech Warrior 2 had some levels happening in a city, made of many, many buildings. The developers at Activision gave normal names to most of them — "hospital", "mall", and such. But the city was really vast, and the developers predicted that players with time to spare would go exploring for the hell of it. And so, far from the road you were supposed to take in the mission, one little building would be identified as "Activision Headquarters". If you blew it up, a nuclear explosion would happen that would destroy everything, mission objectives and player included. Time to reload...
In one of these cities, you can find a building far on the perimeter named "House Jack Built". If you run up and inspect it, it contains Jack.
Likewise, Mechwarrior 4 features a pair of missions set in a city, with some buildings labeled hospital, corporation, data center, and FASA Interactive. You can't blow it up, though.
Miscellaneous
Star Trek: The Game Show, a PC game hosted by the character Q, will give feedback based on the scores earned by the players as they enter the final round. In one game in which there was a massive disparity in the scoring, Q's remark after reviewing the scores was, "Well — I see one of you has a life."
In the Super Sentai arcade game Dice-O, one of the Special Attack cards you can use is the Gokai Galleon Buster; the animation has each of the characters involved using their own Ranger Keys to power the Buster. This even extends to Space Sheriff Gavan, who never had a Ranger Key to begin with.
In Analogue: A Hate Story, early on the player prompted to unlock a numbered "block" of text files through the command prompt. Later on, the same instruction is given for a different block; if the player has already unlocked the block with the command, a line of text is displayed acknowledging the player's ingenuity.
The Mystery Case Files casual games' developers tend to Think Of Everything a player might do, however odd or counter-intuitive. For example, in Escape From Ravenhearst, you can run every object accessible at the time through a scanning device, and see its X-ray image; if you're playing the Collector's Edition in which tokens must be gathered and energized, the tokens' scans show sparkles after charging, just like the tokens do.
Space Ace has the energizing scenes, in which Dexter turns into Ace. If, when you get to the energizing part, you choose not to energize, Dexter remains that way throughout the entire level. The motorcycle level had the event of not energizing into Ace the shortcut to clearing the level; Dexter goes down the ramp screaming, shoots the pig bikers, tells Kimberly to get on, and Kimberly gets on.
Dexter: AHHHHHHHHHHHHHH!
Dexter enters the vault.
Kimmy: Dexter, you're late.
Dexter shoots the pig biker.
Dexter: Come on.
Kimmy: Dexter.
Dexter: Call me Ace, huh?
The roller skate level also was short if the player did not energize. Dexter says, "Use the aquaboots!" And then, after shooting the eel, the level ends.
Even the "dark side" fight is different: if the player energizes into Ace, he has to fight a giant Ace, but if the player doesn't energize, then instead, Dexter has to fight multiple regular-sized clones of Hexter by avoiding the blasts that the the Hexter clones fire... TWICE!
The CD-Rom Star Trek Encyclopedia, released in the late 1990s, was programmed to be compatible with voice-recognition software so you could, for example, say "James T. Kirk" and pull up an entry on him. This included an Easter Egg where, if you said the phrase, "Tea, Earl Grey, hot", the program would respond, "This is an information kiosk, not a replicator."
MMORPG
Star Trek Online is starting to work its way there. More recent missions have had numerous failure conditions and alternate methods of accomplishing goals. In the Romulan series, for example, there are several Dialogue Trees, with new options opening up depending on the character's diplomacy level and several sections where a violent character could blast through without even talking at all. There are numerous points, even in the earlier missions, where a sufficiently sneaky character can approach enemy soldiers and eavesdrop on them to learn potentially useful information ahead of time, which they wouldn't have heard otherwise.
World of Warcraft: back in the days before the Cataclysm expansion pack was released, if you went through a demon-infested gorge, jumping in exactly the right places and using a since-patched glitch known as wall-walking (which was literally jumping up a normally untraversable wall or terrain in a very precise manner to trick the game into thinking you've grabbed a foothold), you could enter the then-uncompleted Mount Hyjal. When you got there, you found a zone that was actually fairly fleshed out, including the skeleton of Archimonde. The actual note that merits this entry: construction signs telling you you weren't supposed to be here and better get out, and you would receive a debuff called "No Man's Land" that instantly teleported you out even if you somehow manage to enter it. There were even rumors that you would be automatically reported to a GM upon receiving the debuff, as the player would have had to deliberately and willingly break the rules of the game by using an exploit several times to get there.
Also, when water walking didn't apply to mounted people and it was nigh impossible to get to it, an island to the south east end of Kalimdor had a message in a bottle with, basically, "How did you get here?!"
If you make a rude gesture at Mountaineer Pebblebitty (which you are likely to do, considering what she puts you through), she has an appropriate response ready.
Most city guards will react to emotes, /rude them, they respond in kind, salute them, they salute back, etc. etc.
The Mists of Pandaria quest "Li Li's Day Off" requires you to take your NPC follower (a kid up for some sightseeing) to three predetermined places she wants to visit. However, you can take her around on a tour through the entire Valley of the Four Winds zone first, which, while not required by quest objectives, will make her comment something about every place you visit. She's very much a Little Miss Snarker, so taking the full tour with her is worthwhile at least once.
The Dominance Offensive storyline for the Horde in patch 5.1 makes you constantly travel to various locations, mostly by asking the indigenous Tak-Tak to give you a kite ride. However, one piece of the long quest chain asks you to travel to Silvermoon City, which is on another continent, and to boot, about the farthest from Pandaria that you can get. The quest designers expect you to take the portal; if you speak to Tak-Tak instead, he says, "I ain't flyin' a kite to Silvermoon City! You crazy?"
In Warhammer Online, the devs watched alpha testers get to some pretty strange places, and rather than fixing it, they either added kegs of dynamite to blow yourself up, so you can respawn where you are meant to, or by adding high level boss characters you can fight if you can get an entire party to that spot.
The same thing happens if you hit Yes, then No; for Yes, the old man says "You don't know the importance of parents until you lose them..."
A magic shop keeper in RuneScape gives out free Mind Runes and Air Runes every five minutes or so. Trying to sell the freebies back to him will net you a sarcastic comment.
There was a glitch where it was possible to enter the Draynor Bank Robbery cutscene, and pick up the Blue partyhat that would drop. This partyhat actually has a different Item ID than the regular Blue partyhat and is untradeable. If the player attempted to equip it, it would disappear and a message in the chatbox would say, "Please send in a bug report and tell Jagex how you got that hat."
In the Pirate's Treasure quest, the player is only supposed to smuggle the Karamjan via the banana crates. All other methods (teleportation, etc.) will cause the player to lose the rum.
No longer true, as of 2013 there's currently several methods in the game to smuggle the Rum, most of which are detailed here
In City of Heroes, most of the zones in Paragon City are walled off. However, if you're in Peregrine Island and you swim to the edge of the zone, it instantly moves you outside the walls of Talos Island. Bear in mind the outside-the-wall zone is horribly horribly broken, but this seems to be a case of a good bad bug.
Kingdom of Loathing: At one point during the Sauceror's Nemesis Quest, they create a potion that turns them into a slime, allowing them to infiltrate the slime convention. You can't use skills and are treated as though you don't wear any equipment. So, totally useless. Now, there is a bonus dungeon inhabited by other slimes called the Slime Tube. It is a rather high-level zone, usually reserved for Aftercore. so, if you go into this tough area in that useless form, you get an Easter Egg.
Ko L has special messages for certain things that can only be obtained through exploits, such as finding plurals for unique items (Ex. The plural for Emblem of Ak'gyxoth, an item rewarded to the very first person who summoned Ak'gyxoth, is Emblems of Ak'gyxoth, you dirty exploiter), or trying to do unclickable actions via http links (Ex. Attempting to use a Comfy Sofa without owning one will result you in falling to the floor and taking damage). Hot stuffing, an item that can only be crafted by using a Javascript command, is listed in the Discoveries section under the "Dirty Exploits" category.
Violet Prentiss, one of the first Prentiss Tigers' contacts in All Points Bulletin, wears an outfit that resembles a cheerleader outfit. If you try to look at her rear by looking under her tutu, you'll be rewarded with seeing a nice pink tattoo saying "Pervert".
Multiple
Many games have intentional safeguards to prevent the game from crashing or entering the territory computer programmers euphemistically refer to as "suboptimal performance." In this case, it's not really "thinking of everything," but just good programming technique - assume "everything" is possible, and plan accordingly. A good example is the Chris Houlihan room in The Legend of Zelda: A Link to the Past, which is loaded whenever the game can't find the proper room data for where Link is supposed to be. Final Fantasy VI has tons of such "default" data, such as default monster reward data (which, if you're curious, is a Thunder Blade or a Jewel Ring, with no EXP or Magic points).
Sonic The Hedgehog 3 and Sonic 3 & Knuckles also had a similar failsafe system — if the game ran into an internal error, it would simply load up the Blue Sphere minigame instead of crashing. Specifically, it would soft-reset first in response to a few errors.
As did Sonic 3 D Flickies Island. Whenever the cartridge was slightly tapped, it could cause small errors, and the game would take the player to the "secret level select screen", which works just like the regular level select screen.
Party Game
In the Jellyvision quiz game series You Don't Know Jack, certain questions require you to type in an answer. The inevitable response will annoy the game's host, who will deduct a ridiculously large number of points from your score. If you do it twice, he will lambaste you and pointedly remove no points for not being original. If you manage it a third time in a single session, the host will give up on you and force quit the game.
Also, in many versions, if you buzz in to answer before the question appears, rather than having multiple choice answers, you have to type in the exact answer without ever knowing the question.
And if you DO know the question, due to playing the game multiple times, the host will give you the points for a correct answer, but accuse you of cheating, unless you're playing the demo (which only has a few questions), in which case he will ask "how many times have you played this demo anyway?"
In newer versions, however, buzzing in too fast will give you a bunch of nonsensical gibberish phrases for answers, all of which are wrong.
The in-game audio will vary based on your computer's date and time. If you fire up a game at 3 a.m., the host will be groggy. Or he'll call you a loser if you're playing on a Friday night.
Some wrong answers, even to open-ended questions, have custom responses.
Platform Game
In Conkers Bad Fur Day for the Nintendo 64, the player has the option to input cheat codes in the options menu near a fire imp apparently warming his hands. Typing in a wrong cheat code prompts the fire imp to remark "Somebody told you the wrong cheat".
When the player inputs the same cheat code two times in succession, the fire imp insults the player.
Whenever a swear word is put in place as a cheat code, the imp takes the word as an insult.
At one point in Psychonauts, you have to go into the minds of a few people to assemble a disguise to trick the warden. A lazy or creative player might think that just jumping into the warden's mind would be quicker. The game will let you try it, but all you'll get is an amusing note explaining that the warden is protected against psychic interference. Similarly, if you try to jump into any of your fellow campers' heads, you'll get a notice saying that the mind-jumping-device won't work on minors.
In the normal course of gameplay, after saving the turtle Mr. Pokeylope, you carry him for about 30 seconds before losing him forever. If you decide to take Mr. Pokeylope to camp after saving him, every camper reacts to him in different ways, mostly involving how adorable he is. In fact, almost every NPC in the game reacts differently to every single power-up you use on them, and every item you could possibly show them. One particularly amusing example: Using the "Rose" item from Black Velvetopia on the dog painters will make them tell you to "Go find someone your own species."
The PC version on Steam even made showing him to all the campers unlock an achievement.
The Lungfish Call item makes a... specific sound. Using it near Dr. Loboto has him tell Sheegor to "go outside if [she's] going to do that."
Some of the best responses to the Confusion attack show up in Fred's mind, which is cleared of its inhabitants by the time you're technically supposed to be able to get Confusion.
Using cheats early in the game allows you to use powers that you're not supposed to have yet on characters that might not be around at the time you're actually supposed to have the powers. Using cheats in this way often results in amusing dialog that you wouldn't hear if you played through the game normally. Using confusion on the G-Men is particularly hilarious. "Oh my God, why am I holding a gun?!"
Clairvoyance allows you to see through someone else's eyes, specifically permitting you to see the world as they do. Each and every single character in the entire game, including every single enemy type and random animal just hanging around, sees you differently. Seagulls see you as a cat, Censors (basic enemies) see you as a virus, your love interest sees you as a dashing prince, each teacher, each child, every single mob that appears in the game. Every single one. And those agents in the Milkman's Conspiracy? They see you differently depending on what you're holding.
Much like with the warden, if you just try to steal Gloria's award instead of going into her mind with invisibility or telekinesis, you get unique scenes where she thinks the thing is going off on its own and won't let it leave anyway.
Iji has plenty of hidden material... but only if the player thinks of everything, too. (The fanbase usually finds secrets relatively quickly, but still.)
Duke Nukem 3 D, there's one level set in a generic rocky, desert area, with a particularly annoying bit where you have to hit a few switches inside a closed in space, with shrinker bolts being fired at you from a seemingly random hole in a far off cliff face. There's no footpaths there, and the jetpack can't take you that far. Activate the fly or noclip code, however, and entering it shows a long tunnel with a static, scripted shrinker at the end, and a graffiti-like graphic stating "You should not be here!" along the tunnel wall.
Duke Nukem 3D is famous for several such surprises. The level that ends with a helicopter waiting for you outside has an invisible panel that can only be seen from the other side — inaccessible without the use of the noclip code. On the visible part, it says "You're not supposed to be here". In a later level, yet another similar wall says "You're not supposed to be here... either" (confusing players who happen to find the second wall but not the first). The level designer who made those levels (the infamous Levelord) is known for surprise messages like these.
In the Steam edition of Eversion, editing the game's files nets you the achievement "What Have You Done?" and locks out getting anything else until you undo the changes.
Super Mario 64 allows players to leave the level they're in at any time. There is a catch to this: you can only leave if Mario isn't moving. If you pause while Mario is in motion, there won't be any options to adjust. The dev team probably knew that players would try to leave the level if they were about to die, so they disabled the option if Mario is not standing still.
You can, however, use it to avoid drowning by just floating still in water.
In Super Mario 64 DS, the portrait used to unlock Wario is accessible only with Luigi. Inside the painting, you can find hats that transform you into either Mario or Wario. The boss of the level has unique dialogue for each of the three hat-wearing heroes. Yoshi, however, has no hat, so you cannot transform into him inside a level, and Wario's portrait cannot be accessed by Yoshi. However, by hacking the game, you can fight the boss with Yoshi — only to discover that said boss has dialogue programmed for just such an impossible occurrence.
VVVVVV has one shiny trinket that is impossible to get without dying. So does this make it impossible to get 100% Completion on no-death mode? No, because in that mode the room is actually altered to make it possible to get without dying. This special version of the room is named "I Can't Believe You Got This Far" (or "Imagine Spikes There, If You Like" in timed run mode).
Because of its extremely non-linear nature, Banjo-Tooie occasionally places Shock Spring Pads in areas in which the player could potentially get trapped, by getting there before learning the necessary moves to get out. This includes Area 51 in Witchyworld, in which the player would have to skip an early move and enter from a later level in order to get trapped, and Grunty Industries' Quality Control room, in which in order to get trapped, the player must glide over the barrels with Kazooie rather than entering as mechanical personnel.
In Epic Mickey, there are two points in the game where Mickey visits Tomorrow City's rocket launch pad. Hidden in this area is a dog collar, an item for Mickey to retrieve in an optional sidequest. During the first visit, this sidequest is still ongoing, provided Horace has started it, so Mickey can grab the dog collar and return to Mean Street to give it to Horace. The second visit, however, is near the end of the game and is after the Point of No Return, so Mickey can't go back to Mean Street to finish the sidequest. The dog collar is still there, and Mickey can still take it, but your Exposition Fairy Gus will tell you there's no time to waste instead of telling you to return it to Horace.
Mega Man 9 has a nice little extra bit of details in regards to its penultimate cutscene. Upon defeating the last Robot Master, you'll get a chip that contains a recording of Dr. Wily's speech to Dr. Light's about-to-be-scrapped Robot Masters just before reprogramming them for evil. Attentive players will notice that in that scene, only seven Robot Masters are present. More attentive players will notice that the missing Robot Master is always the last Robot Master the player defeated, since it's supposed to be that moment through that Robot Master's eyes.*
Interestingly enough, they didn't fix the moment immediately before that one, where the word "he" is used even if you defeated Splash Woman last.
Puzzle Game
In Portal, it is possible for creative players to trap either themselves or vital objects in inaccessible locations by using portals. When this happens, the AI running the test will either let you out or provide replacement equipment, while making a sarcastic jab at your ineptitude.
The XBLA re-release even has an Achievement for managing to trap yourself in a room.
It became a requirement during the "Transmission Received" bonus quest as one of the radios is hidden in such a room.
The in-game commentary track even points out a place where testers discovered a way to sequence break a level. Normally, Valve would just alter the level to make the sequence break impossible, but since they realized that such Sequence Breaking required more knowledge of how the game mechanics operated than the level was trying to teach, they decided to Throw It In and let the player continue anyway.
Of course, there is at least one area where you can be trapped, and she won't release you. Not that it would make any sense for her to free you after her botched murder attempt.
Portal 2's challenge rooms feature a crossed flag decal to indicate the end of the trial. During the first escape sequence, you'll find one of these at the door leading into Glados' trap which disappears when you get close.
A few minutes after that segment, Wheatley has to "hack" the door to a turret scanner, and asks you to turn away so he can do so. If you use the portal gun to watch him, he'll tell you "that's not fooling anybody".
Wheatley pretty much has something to say for anything you do in the game.
On the level 「King of the Jungle」, if you ring Wiki in the proximity of the King, he will walk towards you. The player can exploit this by ringing Wiki while separated by a cliff, and you can sneak behind him and itemize him. The player gets a bonus treasure for doing this.
In Peggle, if you are using Reinhart, the first bar of Toccata and Fugue in DMinor will play when you hit the power up peg for Spooky Ball (which makes the ball wrap back to the top after falling off the bottom of the screen), and then the second bar will play when the ball wraps. Hit both power up pegs on one ball, or the second one after the wrap? Instead of repeating the first two bars, the next two bars of the Toccata will play. Plus, no matter how you did it, all four bars will play in order.
You can ask your allies to send you backup, or to attack an enemy at any point in the game. If they have enough resources, they comply. So why not keep sending them to do your dirty work? Because sometimes they will ask for gold in exchange for it, especially if they suffer heavy losses in the battle they started because you asked. If you keep pushing, they'll renounce their alliance with you.
You can take your allies' help in building up resources by asking for gold, food, wood, or stone as is necessary to you. They'll give what they can spare. One might think there's nothing to stop you from leeching resources off the other players, but if you keep doing this they'll simply deny your request.
If you threaten to kill a CP player unless they turned over a ridiculous amount of gold, the AI could respond by declaring war.
Similarly, an enemy CP player will sometimes voluntarily offer alliance in exchange for resources if they need some food/gold/whatever fast.
On the other hand, if an allied player gets rich enough in resources that they don't need your help any more, they might just declare you their enemy and start a war.
The one way to avert this was by building as many of your buildings as possible inside the allied player's area, so that if he turned on you, your troops and military buildings would already be inside his perimeter, leaning the advantage in your favour and making them think twice. But then they went ahead and released the Conquerors expansion pack, in which other players will make you pay tribute if you encroach into their territory too much. Failure to comply will result in war.
In Starcraft, the Protoss faction had Dark Archons, with an ability called Mind Control, allowing it to take control of enemy units. A creative individual might try to take control of a critter and discover that the game would let you do this. Then they would discover that critters don't show a faction color, making them the best scout units in the game. It's worthless in highly competitive play, but fun to spring on unsuspecting Battle.net players.
It can also be used to gain control of "constructor" units, which can be used to create that enemy's buildings and units under your control; effectively allowing you to double, or even triple, your forces (depending on resource availability).
In Star Craft II, certain zerg ranged units, such as the roach and hydralisk, have a special melee attack that triggers when enemies are in range. It's functionally identical to their regular attack, but uses an animation of the creature attacking with its claws instead of projectiles.
Not exactly identical to their regular attack. It will not trigger terran Point Defense Drones, making it possible for them to attack even while under a PDD if you move them right up to melee range. This is only likely to be useful in 0.1% of games... but it's there.
Also in Starcraft II, there are two missions ("The Devil's Playground" and "Welcome to the Jungle") where your primary objective is to defend your base, ignore the enemy's beefed-up defenses, and harvest a certain amount of resources from the contested area. However, you can win both by ignoring the stated goal, building up your forces, and wiping out the enemy base. There are even hidden achievements for doing so. Similarly, you can win "The Dig" by blowing up all three hostile bases, if you'd rather not wait for your mining drill to finish digging.
Similarly, in the Brood War mission "Kel-Morian Combine", you're supposed to harvest 10000 crystals while fending off attacks of five Terran factions, with a bonus of any Infested Command Center carrying over. Should you Infest all five Command Centers, you automatically obtain the requisite 10000 crystals and finish the mission. And in the very same mission, it's possible to abuse the AI behavior by attacking the enemy bases outside of the suggested order. Because of the five bases, only the two weakest at the given time send their attacks aganist you, and the rest (including the Battlecruiser-toting one and Nuke-dropping one) aren't moving.
There's also Starcraft II's "Smash and Grab" mission, where you're supposed to reach the artifact, before the Zerg get to it through Protoss defenses, while ignoring the Zerg-Protoss fighting — but you can attack the Zerg, which prompts this conversation:
Tychus: This is crazy, man! We can't take the zerg in a stand-up fight, and you know it!
Raynor: Leave the tactics to me, Tychus.
Starcraft II has a lot of tidbits that show a near-maniacal obsession for detail. For instance, every Terran non-combat unit you find in the cities you fight in has a small creative description if you click on it and hover over the unit graphic. What to do with all this pointless stuff lying around? Well, Blizzard knows their players, and they rightfully assumed some of them would destroy the neutral units just for the hell of it. And so, in Heart of the Swarm's Ultralisk evolution mission, destroying one of many vehicles present on the map will cause an angry Marine to come out of a building, yell "My car, man! I just paid that thing off!" and single-handedly attack your Ultralisk army.
In Command And Conquer Tiberium Wars, clicking on units in combat will result in different quotes than if they were idling or moving. Ordering units idling to return to the area near a base will result in alternate quotes as well, while telling units in combat to return to the base will result in them yelling retreat orders.
And the devs of Command & Conquer Tiberian Sun programed in a number of interesting details: Artillery shells deformed the terrain, bridges collapsed if you sent too many units over them at once, train cars rolled down hills if they were on a sloped track (keep in mind, this was a pretty old game), and EMP cannons could sink hovering vehicles if they were driving on water. Also, defending a base could be a lot more interesting with a veinhole nearby.
Mammoth tanks could also be ordered to walk across frozen bodies of water...and sink if the cracks their weight creates get too big and the ice gives way (keep them moving to avoid this).
Both Tiberian Sun and Tiberium Wars feature bridges made up of multiple segments. If you destroyed a segment, the others would stay up — unless you cut a span off from solid ground on both ends, at which point it would promptly collapse.
If a wheeled vehicle was destroyed near water, the wheel could possibly roll all the way to the water, which would cause a splash, and then sink, with a unique sound effect!
In Red Alert 2, you could use the Chronosphere to pick up dreadnoughts or carriers and drop them onto enemy vehicles or structures, inflicting a surprising amount of damage.
Also in Red Alert 2, the Allied Spy could infiltrate enemy Battle Labs, giving you a special unit — the Psi Commando for a Soviet Battle Lab, and the Chrono Commando for the Allied Battle Lab. However, if you also had the ability to build Soviet units (either by capturing Soviet buildings, or by being a Soviet player who gained access to Spies), you got two other units as well: the Chrono Ivan for the Allied Battle Lab, and Yuri Prime for the Soviet Battle Lab.
This was removed in the expansion Yuri's Revenge, but the units remained. Now, using a Spy to infiltrate an Allied Battle Lab gave you Chrono Commandos, a Soviet Battle Lab gave you Chrono Ivans, and a Yuri Battle Lab gave you Psi Commandos. Yuri Prime, meanwhile, became the Hero Unit for his own faction.
In Star Wars Galactic Battlegrounds (think Star Wars Age of Empires), the first Wookie campaign mission has the player start by rescuing four workers. This makes sense in the story context, and allows the player to repair later units to a limited extent, but the player doesn't have enough resources for the workers to start building a base (and being the first mission, it is fairly easy to win with what the game gives). However, if one uses cheat codes to gain resources, build up a base, and eventually explore the blocked off sections of the map, the mission goals drastically change and the player has to perform a completely different task, but completion of the new objective wins the mission and the story moves on as it would have otherwise.
There are other little bonuses thrown in for those who cheat to see the full map, particularly in missions without air power, when certain sections of the map are theoretically inaccessible.
Tusk's ultimate ability Walrus Punch in Dota 2 causes text to appear when it hits: "Penguin Punch" if he hits a creep by mistake, "Seal Punch" if he hits a hero normally, "Polar Punch" if he hits a hero below half health but doesn't kill them, and "Walrus Punch" if he hits a hero and kills them. Rubick, another hero, has a spell that lets him steal other heroes' spells. If he attacks with a stolen Walrus Punch, the text will instead say "Stolen Punch," or "Sucker Punch" if he uses it right back on the Tusk he stole it from. Rubick also has unique animations for many stolen spells, such as using his staff as a rifle to imitate Sniper's Assassinate, riding his staff like a broomstick for Batrider's Firefly, or sticking out a finger gun for Lion's Finger of Death.
Roguelike
In Dwarf Fortress, if you piss off the humans enough to start a war after letting their guild representatives wander through your fortress, they avoid any traps said representatives have seen.
There was a report on the forums a while back of a dwarf that got disemboweled and somehow managed to recover. Everywhere he walked, he'd trail a little "~~". ASCII Gorn strikes again.
If a standing unit loses the ability to stand (either from legs/nervous system injury or losing consciousness) and has another unit's weapon stuck inside them, they continue standing up because the game can actually tell the other guy is holding them upright.
In Adventure Mode, kobolds that are within the player's field of view but in the dark show up as ", to represent their glowing eyes. If the kobold in question has lost an eye, it will show up as '.
For example, arrow traps can be triggered by any kind of movement, which means a careful spelunker can use them to kill monsters for him or drop rocks to trigger them safely from above. He can sometimes retrieve the arrow to use as a weapon.
The shopkeepers have different responses for different actions. Steal? "Thief!" Damage their shop? "Vandal!" Light a bomb in the shop? "Terrorist!"
If you approach a shop after killing a shopkeeper previously, "You'll pay for your crimes!"
If you attack the Damsel in one of the kissing parlors:
"Hey, only I can do that!".
Stones that are sent flying by explosions can injure or kill anything they smash into, including the player.
The Man-Eating Plants can be used to dispose of annoying cavemen or any human-sized enemy, either by putting one in their path, or by throwing them into it.
Bombs can be used to destroy traps or prevent certain traps from triggering, and may also be used to remove pools of water and lava. Clearing out the pools of water will kill any fish swimming in them.
The pools of water in the Lush area can drown spiders. *
Unfortunately left out of the remake.
You can stick an arrow into a wall and use it to climb higher — IF you can throw it fast enough.
The Thwomp-ripoffs can smash through the falling platforms.
Said falling platforms can be used to squish enemies, as can movable stone blocks.
Destroying a shrine to Kali causes spiders. Do it again and you get punished with a ball and chain. Third time lucky? It spawns a ghost and makes the level dark. Oh dear.
Man-eating plants promptly explode when they devour live Shopkeepers and Fire Frogs, although the former, if not damaged enough, often survives. *
On the other hand, you can take advantage of the brief time the shopkeeper is stuck inside the plant to grab his shotgun.
In the unlikely circumstance that two trees in the Lush area are generated side-by-side at the same height, their tops will form one long canopy.
It is possible to kill stunned enemies by throwing them onto spike pits.
If you pick up an item in the shop but figure the price tag is too steep, then you can always blow up the shop, right? If you touch the merchandise, walk out, and attempt the Ballistic Discount technique above, then you will be shot the moment you light the bomb instead of when you throw it into the shop. The Shopkeepers are on to us! Run!
(In the remake.) Normally during the ending, when the character(s) are flung out of the volcano, they land into the sand, but if any/the only player(s) have a parachute, it will deploy and they float gently down.
Large "loose" stone blocks can be pushed to trap and squish enemies, including the shopkeeper.
Role Playing Game
In Lufia: Curse of the Sinistrals, there is a point where there is a tutorial for Tia's grappling hook move. If you move the box ahead of time then trigger the event where Tia is about to explain what to do, Maxim will note there's nothing where the game's camera is focusing.
In the English Fan Translation of Treasure Of The Rudra, you can not only type in the words given, you can type in English words. Or in some cases, Japanese romaji of the same concept (hikari, for instance, will produce light, as will the word light). Knowing which word produces the best effect for the amount of MP, however, is part of the challenge.
Interestingly, one particular NPC (Bolvyn Venim, Archmaster of Great House Redoran) is plot-essential in that he has to be killed at a specific point to complete the main quest. Since Morrowind had no means of toggling the "Essential" flag mid-game (unlike later Elder Scrolls titles), Bethesda instead wrote a custom script for that character that would mimic the effects of the flag if that NPC died at any point than when and where he was supposed to.
In the Redoran quest line, you have to convince a faction member to duel a much more heavily armed Hlaalu opponent in the arena. You are explicitly told to watch the duel without getting involved. The Redoran man is doomed - unless you are a mage with a long-range healing spell. After surreptitiously helping him win (and you have to be a pretty good mage to pull this off, even though Redoran is the fighter's House), he will tell you how surprised he is with the results of the fight.
In The Elder Scrolls IV Oblivion expansion Shivering Isles requires the player to choose a side as the ruler of Mania or Dementia. Sheogorath prohibits the player from entering the opposing faction's castle, and his edict is enforced by an invulnerable guard. However, even after the player replaces Sheogorath as ruler of the realm, the guard still refuses to allow you passage. The excuse is that as "Sheogorath," you prohibited yourself from entering and she must enforce your wish. This actually kind of makes sense given that the Shivering Isles is completely insane.
On that note, if you attempt to do Sheogorath's shrine quest in the main game world after becoming Sheogorath, instead of the usual dialogue, you get a message from your butler berating you for praying to yourself, before then considering that, as the god of madness, it's appropriate.
Even better! If you start the quest with the expansion installed but not started, the dialogue is the same as normal, but the voice has changed from his normal Oblivion voice to his new Shivering Isles voice. AND, if you have started the expansion storyline but are only partway through, Sheogorath's intro monologue will have actually changed to reflect how far along in the expansion you are. All that for an optional sidequest.
Not to mention that if you go to the shrine after becoming Sheogorath, but before defeating Jyggalag, Haskill will get really upset about the fact that the forces of order are mounting a full-scale invasion while you went and offered some yarn to yourself instead of defending your realm.
Infinite Space: Earlier in the game, you are faced with an unwinnable battle against one of the badasses. You have about 100 people against 9999 enemies. Even if you use cheats for infinite soldiers (turning this into 9999 vs infinite 9999), the computer will start to cheat when it will drop below 7000 so you can't win (the minigame is based on RPS). And even if you use the reduce enemies to 1 cheat, you still can't kill the last soldier.
In Golden Sun: The Lost Age, after lighting the Mars Lighthouse, the player controls Felix only, which means that the psynergy 'Mind Read' shouldn't be usable. With the help of ROMs and cheat codes, it can be given to Felix. Using Felix's newfound ability in Prox results in new information in the mind reading dialogue boxes... the developers put Mind Read text in normally non-mindreadable characters. Not just text, which would just be there to prevent the game crashing over an impossible action, but plot hooks.
Atop Jupiter Lighthouse prior to its lighting, Agatio and Karst also have Mind Read text, though Sheba isn't in the party at that time, either. Both are thinking that Felix has outlived his usefulness, foreshadowing the upcoming boss battle. Agatio's thought bubble contains a typo.
It does this quite a bit. In the first game, if you enter Altin Mines without the Force Psynergy needed to cause a path-opening rockslide, Garet will get frustrated and kick a wall, causing the rockslide. In fact, the Force Orb's abscense in The Lost Age if a file from the first game is not imported implies that this is either the defualt scenario, or the developers knew that otherwise people would be asking how Isaac's team completed the first game in a non-import file..
It's possible to go to Imil before Kolima in the first game. If Mia's in your party when you trigger the Kolima cutscenes, the game has extra dialogue so she'll get lines, and it's rumored (though not proven) that Tret's boss fight gets a difficulty boost to account for your larger party and higher level.
If you set Flint to Ivan while he's briefly in your party at Vault, he will apologize and give Flint back when he leaves. This just happens to keep him from being in another class in a later cutscene when he rejoins and uses a power exclusive to his base class.
More recently, it's been discovered that you can glitch-exploit Retreat to skip the part of the game where Mia joins the party. In doing so, you also skip the only part of the game where Mia's unique Ply power is required for puzzles. A boss later in the game provides an artifact that lets other characters use Frost, so you can solve Frost puzzles without her, keeping the game from being Unwinnable by Mistake without her.
Using the same glitch in another location lets you access the other Djinni in Mercury Lighthouse, so you can still get 100% completion in The Lost Age (finishing the first game with 27, transferring data to TLA, and using the spawn point in TLA for the Djinni Mia would have normally given you).
In The Lost Age, if you give the Lash Pebble to Piers and you go to Lemuria, when Piers will leave the party you will need to Lash once to enter the house of Lunpa. However, if you can't use Lash, Lunpa will insult you and throw down a rope instead, preventing you from getting stuck. This is the only use of the "rope throwing" animation in the game.
In The Lost Age, replying "No" to everything eventually results in Kraden throwing a tantrum and accusing Felix of thinking this is all just a game.
When in speaking roles, Djinn also tend to have increasingly-amusing responses to being continually denied, and a character in the first game will complain if you change your mind repeatedly in one cutscene and cause the conversation to loop.
In Dark Dawn, you cannot name your character any name that belongs to another player character or plot-relevant NPC (including Alex). This has not been confirmed for the other two games.
Rhys, the first protagonist of Phantasy Star III, gets tossed in a castle dungeon almost immediately upon starting the game. More Genre Savvy players can sell his boots to raise enough money to buy an Escapipe (which allows you to escape dungeons) before the fact and skip rather plot-crucial cutscenes to escape. On the other hand, doing so will trap you in the castle, where the king (Rhys' father, it should be noted) tells you, in (slightly) nicer terms, that while using an Escapipe is normally a wise move, this particular example of Script Breaking has appropriately broken the game's script, and now reset the game and do it right. Nice Job Breaking It, Hero.
In Phantasy Star IV, Rika mentions the use of Gires, the strongest healing technique available without seriously overzealous level grinding, in a cutscene following a boss fight. If no one in your party has access to Gires when the boss fight starts, he'll spam Forceflash, a powerful attack that hits your entire party for about a half to a third of their total HP — and since you're not at a high enough level to have Gires, you don't have enough HP to survive that more than once or twice in a row. It's (almost) impossible to win the fight without cheating.
Final Fantasy VII has some saves in regards to non-permanent members in your party, giving them lines in cutscenes after the point where they've left in the case player was able to somehow avoid that event (or more likely hacked them in). These being Kid Cloud, Sephiroth, and obviously Aerith. The latter spawned theories that she could be revived. She couldn't. Speaking of that, there's another example directly after the boss battle that follows her death. Each different potential party member shows a different reaction when viewing Aerith's body. All with no dialogue.
When the team first leaves Midgar, Cloud gets to choose his 3 party team member. Having both female team members join Cloud causes a sarcastic remark from Barret. Having both male team members (well, including Red XIII), causes the two ladies to mention that this was entirely unexpected.
And after this, Cloud is technically supposed to join up with the team in Kalm. You can bypass the town, grab a Chocobo, run pass the Zolom and get off the Chocobo. Technically, this would mean you have stranded yourself between the unpassable Mithril Mines and a Curb-Stomp Battle. The dev team was nice enough to save your ass by having Cloud remark that he thinks he forgot something... and can the Chocobo please not run off first.
However, the game will crash if you put party members in your party that you can't get at any point on the current game disc. It's the most definitive proof that Aerith and Sephiroth are not recruitable, despite the rumors.
During the Post Final Boss fight, you're supposed to use Cloud's Limit Break, Omnislash, to finish off Sephiroth in particularly awesome fashion. If you just stand still and do nothing, Sephiroth will eventually attack Cloud. However, the attack is gravity-based, so Cloud can't die from it, no matter what his HP is. And even then, Cloud will counterattack automatically, winning the fight anyways.
During the portion where Cloud is incapacitated and the player instead controls Tifa and later Cid, it is possible to still go to Wutai village and complete its sidequest there if it has not been already. In case they do, Tifa and later Cid will have appropriate dialogue the whole time the player works on the quest.
Similar to the FFVII party choice example above, Final Fantasy VIII features an example after you gain the main six party members for the first time. The six characters split into two groups and Irvine immediately wants to travel with the two cutest girls. Accepting his suggestion leads to him thanking Squall in disbelief. Making him travel with the two male characters will lead to him being annoyed, and a mix will earn you an indifferent "whatever you say".
During the fight against Seymour Omnis in Final Fantasy X, the player, should he have Anima in his/her possession, might consider using it against Seymour. A cutscene will play for that exact scenario, where Seymour will say to Anima "So you are against me as well?! So be it!"
Quite late in the game, Kimahri is forced into a solo boss battle. Because the game is flexible in what characters you are allowed to use on most occasions, it's entirely possible the player has never used (or levelled) Kimahri at all. Solution? The bosses are entirely based off Kimahri's stats, scaling their difficulty so it is always reasonable (and actually quite easy). You can also learn most of the Ronso Rages that you likely missed up to that point, along with two very powerful ones probably intended to be miracle solutions to that very fight.
The entire game is loosely based on this trope. Nothing particularly powerful or irreplaceable can be permanently missed. One aeon in particular requires the destruction sphere treasure from all six cloisters, and one of them cannot be returned to. The programmers avoided this problem by forcing you to collect the treasure on the way out (the chest blocks your path, and automatically opens if you try to squeeze past it).
There is one boss fight early on where you temporarily control Seymour. If you intentionally stall the fight and take damage, you can charge up and use Seymour's Overdrive — the only time you can ever see it, as he won't ever use it against you. Keep in mind that this boss can be killed in 4-5 hits, and building up Seymour's Overdrive gauge can take a really long time.
During New Game Plus of Tales Of The Abyss, if you carried over acquired titles and equipped Luke with one of his alternate costumes as soon as you gain control of him, during an early scene Guy will comment about the state of Luke's hair. Luke insists he's wearing a short-haired wig (Luke's costumes usually start appearing AFTER he cuts his hair). Later in the game, if Luke was wearing a costume before and after cutting his hair, Tear will say, "...You took off your wig to cut your hair?"
In many games in the Tales Series, especially the later ones, different skits will trigger based on your play style, especially if you're doing something weird. In Tales Of The Abyss, you'll get skits for fleeing from too many battles, leveling up too high too fast, etcetera. Those are the obvious ones, but the skits cover almost every aspect of gameplay. For example, if you make characters fight in their bonus costumes, there's nearly always a skit lampshading it. If you forgo cooking entirely for long enough in Tales Of Vesperia, the party members will start complaining about how hungry they are - and there's even a skit chastising you if you make sorbet in the snow or hot noodles in the desert!
In the DS version of Dragon Quest V, the game normally starts with Pankraz suggesting the lead character be named Madason, only to have that vetoed in favor of whatever you entered. If you actually do enter Madason, Pankraz instead suggests Erdrick — this also doubles as a Mythology Gag to the NES-era translations of Dragon Quest I, II, and III.
Similarly, in Dragon Quest III, if you opt to name the main character Erdrick or Loto, depending on the version, the game rejects it with no immediate explanation — because the game is actually a prequel to the first two. You are Erdrick/Loto, but you won't receive that name until the end of the game.
A non spoilery example in DQIII; at the start of the SFC and GBC versions of the game, there is a test to check your personality. Sometimes, the tester will ask you if you like sports. A few questions later, she will ask the question again. Have inconsistent answers, and she will get angry at you and call you a liar. This is also the only way to get a special scenario where the hero is called a thief and liar and must decide whether or not to clear their name.
In Dragon Quest VIII, an old "friend" of Yangus, Red, will send you after the Venus Tear as part of a deal with her. However, it's possible to have gone to the dungeon and collected the Venus Tear without having met Red yet. If you've already got it, the party leaves, but Trode will ask Yangus why they didn't just give her the Tear. Yangus replies they have to make it "look good," because he knows Red will send them after something else if they make it look too easy.
The games in this series avert Non-Lethal K.O. and treat characters that fall in battle as truly dead until they're revived. In most games, this even goes as far as to exclude them from cutscenes, and change dialogue that refers to them (for example, when rearranging a dead character's items, another character is described as doing it for them). Additionally, losing a battle doesn't result in a game over, it just returns you to the last church. So some games will have bosses acknowledge your earlier defeat if you battle them again.
In Chrono Trigger, there is one Hopeless Boss Fight which you are clearly not supposed to win - in fact, Lavos is at its strongest at this point of the game, just to make sure of it. Still, if somehow you DO defeat the game's end boss at this point, you are rewarded to a Developer's Room ending, where the developers complain about why they bothered programming half the game's content if you already managed to beat the game this early anyway.
The Developer's Room only appears if you win in that particular battle. There's another twelve endings (thirteen in the DS version) you can get from killing Lavos at different parts of the game. Some of them change based on other things you've done, such as if you crashed the Epoch. This isn't including the bad ending, however, making the total number of endings possible fourteen.
Also, if you open a locked chest in the past and take the loot, the same chest will be empty in a later era. However, if you open it in the later era first, not only do you get a more powerful version of the equipment the past chest had, but you can also backtrack and get the past chest's equipment, as well. Yay, Temporal Paradox!
Going to the Black Omen in 2300 A.D. causes Queen Zeal to jump down to the entrance and mock you, reminding you that the Bad Future aleady happened.
The Black Omen itself contains many, many of this. The Omen itself can be beat a total of 3 times in the same way as the chest above (so if you defeat it at an earlier Era, the Omen will disappear in all later Eras). While long and repetitive, this yields a lot of equipment (by stealing from the Omen's boss), which is otherwise unobtainable in large amounts (which is needed if you want to fully equip your whole party). Unfortunately, the other bosses remain defeated when you go back in time, and the treasure boxes on the Omen remain opened, so the abuse only goes so far.
In Chrono Cross, several Hopeless Boss Fights are possible to win in subsequent New Game+ playthroughs. Some of these fights still force you to lose, even if you win. The most notable is the fight where the player switches bodies with Lynx. If you somehow beat all three of your party members, Lynx slowly walks over to Serge in confusion. Kidd stands back up, staggers over to Lynx, and stabs him, ending the fight and advancing the plot.
Due to the two alternate universes, nearly every character you get can meet up with their alternate-universe counterpart, which nearly universally gets you some extra dialogue. Some of these are even essential to the plotline of certain sidequests. In a similar vein, Poshul can join in either world (she's the only such character), and will later protest Korcha's claim that Serge is the only party member from his own world if she is (Razzly, who always joins in Serge's world, will protest as well.)
Super Mario RPG: in the Kero Sewers, there is a treasure chest that you would normally return to after having stumbled across a Spring/Warp Pipe in Lands' End. If you utilize a trick, you can reach the chest and find that it contains something different than usual. After doing so, you can also get the other contents if you use the Lands' End route later on.
Likewise, if you try to Sequence Break by going down a pipe you're supposed to arrive at the Kero Sewers from Lands' End through, an enemy mook will pop up from the pipe and tell you not to go there. Thanks to a large cliff, you can't proceed further from here, you have to go through the other way and knock down a barrel that gives you a boost allowing you to climb up the cliff.
Lose to the Snifit that wants to join Booster's Gang. Then visit Booster's Tower after defeating Valentina. You'll run into the very same Snifit proudly declaring that he got in. You can repeat this with other Snifits in the same way, until the last Snifit says that he would have gotten in, but there wasn't enough room.
Also, if you've defeated Valentina and decide to climb back to the top of Booster's Tower for any reason, you'll see a scene that sets up part of the ending.
The first two Paper Mario games feature tattles for every page, character, and enemy in the game.
If you miss out on tattling on a boss (most can only be fought once, and are then lost forever), that particular boss's tattle entry can be found in Professor Frankly's wastebasket.
Mario & Luigi: Superstar Saga has a few powers that involve doing something like lighting Luigi on fire, zapping Mario with lightning, or hitting each other with hammers. Before you are told you can do this, it's actually fully possible to zap Mario, burn Luigi, or squish Mario and Luigi. However, the other brother turns around and growls at them when you do this. After they learn the ability corresponding to it, they no longer shake their fist at the brother who just burned/zapped/crushed them.
One of the first moves the brothers learn is the High Jump, where Luigi bounces off of Mario's head to jump higher. One NPC wonders what would happen if Mario moved out of the way before Luigi lands on his head. If you start the High Jump, and then move Mario back out of the way, a *ding!* is heard and 1 Coin is added to your money count.
Alternatively, you can have Luigi start the high jump, and have Mario jump into Luigiwhile he's above him. This also gives you one coin, but Luigi actually loses 1 HP and you can keep doing it as long as you mash A, although you stop earning coins once Luigi's down to 1 HP.
Mario & Luigi: Bowser's Inside Story has quite a few examples of this, such as in the final level. Normally, only Bowser can fight the last few types of enemies. But when Mario and Luigi fight them via Action Replay, they're all possible to dodge or counter attack as the brothers. For example, Mario or Luigi hammer away the Dark Mechawfuls when they punch, jump to break the bricks thrown by Naplocks, etc. Okay, it's not perfect (the final area has major issues, at least the bit before Dark Bowser), and one enemy attack causes you to have to just wait it out for three minutes as it does nothing, but it's better than the game freezing as expected. You can also do this with other Bowser-only foes, like the Choombas, which have Mario- and Luigi-specific attack patterns.
Semi-famous example from EarthBound: at one point in the main game, you are required to detour through arain forest to remove an obstacle from the main path; walking through any of the numerous puddles there is accompanied by an appropriate splashing sound unique to the area. The real kicker, though, comes after you've beaten the game and are walking alone back along the aformentioned "main path" to your home. You might have forgotten by this point, but way back in the first town, you got a free bicycle that you haven't been able to use since the second town when you got your first party member (since they don't "stack", and riding around while everyone else has to walk would be rude). IF, during this post-game trip, you decide to go out of your way to revisit the rain forest, and IF you remember your bicycle and take it out of storage (because that's where you've put it, guaranteed), riding it through those same puddles has its own completely different sound effect, which plays at no other point or under any other conditions in the game. A rather Zen approach to the Bragging Rights Reward, isn't it?
Some dialogue also changes depending on who's fainted in your party. If Ness is unconcious and you talk to a random NPC friend of his, the character may ask where Ness is and how you know him.
Another one from the series — in MOTHER 3, Duster is nicknamed Lucky at a point in the game. If you name him Lucky, the nickname will be changed to Gorgeous.
MOTHER 3 is filled to the brim with Easter Eggs and things of this nature; "All the little things" is frequently cited as the 'best part' of the game. For example: Kumatora loses PP when she uses a PSI attack in a cutscene; dialog from NPCs and checking the scenery changes with each event flag. There's a newspaper in a nursing home that the player will likely never check more than once, but its contents change with each new chapter, sometimes more often. When a certain character dies, the dialog viewed when checking the scenery in their home will begin referring to them in the past tense. This blog post and comments detail just a bit of it.
If one is caught using a cheat device in Persona 3, the game will let you know it. Not by screwing your save or throwing monsters out the yin-yang at you. Oh Crumbs no, what it does is have your Navigator verbally admonish you for your cheating ways; it's fully voiced, too!
Fuuka: *Gasp* You're cheating!
Pretty much every Shin Megami TenseiBonus Boss qualifies for this trope so that the player can't use their most game breaking skills or be Nigh Invulnerable (such as using Masakados, Null Attack, or Omnipotent Orb) for these fights. If you break the rules, you're usually hit by an attack that deals 9999 damage. The HP cap being 999 in these games makes it impossible to survive such an attack, of course. In Persona 3, it's actually possible to survive these attacks with the combo spell Infinity, but it only lasts for 1 turn, and if you break a rule the Bonus Boss will just keep using their 9999 damage spell until your SP ends and you die.
Noah from Nocturne also qualifies. He's a Barrier Change Boss that repels all affinities but one. Many players who have faced a Barrier Change Boss in other SMT games would try to bypass this by using Almighty spells, since Almighty cannot be reflected. Noah only takes 10% damage from those.
If you use a PC tool to extract all the voiceover tracks from Lunar 2: Eternal Blue Complete, you will find one track of Zophar praising you for "illegally" ripping the voice data.
In the early parts of Knights of the Old Republic II: The Sith Lords, you can take control of a Czerka Corporation protocol droid and use it to expose the company's corruption. You could just head straight to their offices and download the data from the mainframe — or you could have the droid wander all over the station, listen to unique reactions from every unique NPC you encounter, and cap it all off by convincing another protocol droid to embezzle credits on your behalf.
It's possible to gain Force Sight fairly early in the game, which allows you to see characters through walls and their force alignment. If you use it to look through the closed door and into Atris' chamber, you will see that she has fallen to the dark side.
If you cheat to get higher than possible starting stats in Vampire The Masquerade Bloodlines, Smiling Jack will tell you to do it again fairly.
Even better, if you're playing as a member of the insane Malkavian clan, you can tell him that Malkav (the clan's legendary founder) changed your stats.
In one quest, you must get rid of an annoying ghoul-associate. You can 1. Get her to leave town 2. Kill her in an alley. But if you've encountered the monster woman in the abandoned hospital who relies on flesh to survive, you get 3. Tell her that she needs to meet with a person in the hospital. Cruelty Potential indeed...
A few bits of dialogue in the game make an offhand remark about your appearance with no gameplay effect. These actually will be different depending on the appearance stat of your character.
The developers of Kingdom Hearts thought of what would happen if one decided upon Sequence Breaking and so had cutscenes involving Maleficent changing if the player does so:
Normally, Maleficent spots Alice wandering into her chamber in Hollow Bastion, but if one completes Deep Jungle before sealing the keyhole to Wonderland, Snow White wanders into Maleficent's chamber instead.
If one skips Monstro, the scene where Maleficent grants Riku the power of darkness will play at the beginning of Neverland instead.
Complete Hollow Bastion before going to Olympus Coliseum (for the first time) or Monstro, and Maleficent won't appear in those two worlds because she's, well, dead.
The first fight with Leon is more or less a Hopeless Boss Fight. However, his HP, according to the official guide, is set to 120 during this battle, so it actually is possible to beat him, provided you're careful enough. If you do, you see an alternate scene where Leon falls down, and Sora passes out from the exhaustion of fighting him. (Well, given that Leon's probably the only challenge you've had at that point...)
Kingdom Hearts II also has some of this in the prologue. If Seifer manages to beat you, you get a scene where he brags about having done so, and if you throw the final match to Setzer, he thanks Roxas and gives him a medal.
The move Ingrain recovers HP by digging roots into the ground for nutrients. As a result, not only is regular and forced switching for that Pokémon impossible, there is an element in place that negates immunity to Ground-type attacks from being a Flying-type or using Levitate, which affects exactly one Pokémon that naturally learns Ingrain (Carnivine).
And also Smeargle, who can use Baton Pass to give the Ingrain status to any other party member, including one with a natural immunity to Ground. This even puts the recipient in contact with Toxic Spikes, should they be there.
In every game where breeding is possible, putting two Pokémon of compatible Egg groups will create an egg containing the youngest form of the mother. If you breed a female Nidoran or an Illumise with a compatible Pokemon, said egg has a chance of hatching into their male counterparts—male Nidoran or Volbeat (which are counted as separate species in the Pokedex). Likewise, breeding the males with a Ditto (which can breed with anything) may also result in a female version.
Arceus, a Legendary Pokémon, can have any Pokémon type corresponding to what type Plate it has, and has a different color scheme for each Plate. The move Curse has the type ???, and is the only move with this type (until Generation V, when they've finally classified it as a Ghost-type move). If you hack the game so that Arceus has the same type as Curse, it has its own color scheme and sprites. Also, the event Spiky-Eared Pichu has a Shiny sprite.
The Diamond, Pearl, and Platinum games all have an NPC named Doctor Footprint, who gauges your Pokemon's feelings for you by their footprints. If you show him a Pokemon that doesn't have feet, he'll point that out (but give you a reading anyway).
In HeartGold and SoulSilver, when the player first reaches Lake of Rage, if you fish with the Good Rod you will find only Magikarp. However, if you turn on the radio so that Team Rocket's evolution signal is playing, you will only catch Gyarados, albeit normal blue ones instead of red.
In HeartGold and SoulSilver, the player can do events based on the date (and sometimes the time) to reflect the original games' events. In order to prevent cheating by editing the date and time on the Nintendo DS, as opposed to being "permanently" set on the Game Boy (Advance) era (Gen III) games, the game will effectively ignore date changes until 24 hours or so have passed. For example, if you go to one of the Haircut Brothers, the right brother will show up on the day if you change it, but he'll either say "I have to close up for the day" or "I can only do one haircut a day". However, the game has a loophole so if the player sets the time so that it passes 12:00 AM, then the daily events are reset and can be played over again. Other events, like the Bug Catching Contest event, aren't affected, since there's no way to cheat if you change the date or time.
TMs have changed from being single-use items to have infinite uses, much like the HMs. However, when a Pokémon forgets a move in order to learn from a TM, the move learned with a TM takes on the current PP of the move replaced by the new move. This is to prevent repeated usage of TMs for the purpose of PP restoration.
At one point, the player has to capture Reshiram or Zekrom (depends on the version) to advance the game. However, if your party and PC are completely full — which is very unlikely to happen by accident — this becomes impossible, so the game lets you skip doing so and capture it at a different location after the end of the game.
Because of the flashy cutscene surrounding that Pokémon's plot-related capture, which shows the Pokémon in its default color scheme, there is coding in place to prevent it from being the "shiny" alternate color scheme and spoiling your willing suspension of disbelief. However, there is a "shiny" sprite for it.
Furthermore, starting with Black and White Versions, if the shiny color scheme for a Pokémon is the first one that the player encounters for that particular Pokémon species, the shiny color scheme will be the sprite that is displayed in the Pokédex. In a related manner in Platinum, if the player is traded an Altered Forme Giratina from another player before encountering the game's Origin Forme Giratina in the Distortion World, then Giratina's Pokédex sprite will be that of the Altered Forme.
Morimoto is unique among the NPCs in that, besides him being a real person, his Pokémon carry Petaya Berries. This is an item you can't normally obtain in Pokémon Black and White. If you use any move that lets you obtain a Petaya Berry of his, it will become a Hyper Potion instead.
N's a Motor Mouth. If the player tries to outdo N by changing the settings to the highest possible text speed, N's speech will come out even faster than that speed.
Another Pokemon Black/White example. All Pokemon have two battle sprites: a front sprite that faces the enemy, and a back sprite that faces the player. These sprites are also used for the Pokemon musical. One Pokemon, Mawile, has its back turned to the enemy. So for the musical, in order to keep it from having its back turned on the audience, the programmers switched the back sprite and the front sprite.
Halfway through Black 2 and White 2, you inherit one of N's former companions. If you use it when you challenge N, he will recognize his Pokémon and praise you for raising it.
Also, when Memory Link is activated, you can catch all of the Pokémon N used in Black and White. If you have any of the others, not just the Zorua, he'll remember those too when you meet him by Victory Road.
After getting the DNA splicers and catching Reshiram/Zekrom, if you try to fuse them into Black or White Kyurem and then try to trade it off to an in-game NPC (not that you would anyways) the game says "That Pokemon cannot be traded." as it would result in the permanent loss of the DNA Splicers.
When transferring Pokemon from Generation IV to Generation V, there is a minigame in which the player must capture the Pokemon while they are jumping from bush to bush. Diglett and Dugtrio, who are permanently sticking their heads out of the ground, do not jump—they merely travel through the ground.
Alpha Protocol's story progression runs on this. At first, it just seems like little things, like characters calling you out on wearing ridiculous sunglasses or if you're wearing cammies in a public place where it would be better to wear civvies and blend in. Your character sheet even comes into play, the simplest example being an instance where Mike decrypts some encoded files he's swiped on a mission...unless you haven't put any points into the tech skill, in which case Mike is computer-illiterate and his handler handles the files instead. Multiple playthroughs will reveal just how far-reaching your little decisions are; every choice has a consequence, even dialog options that seemingly do nothing but influence whether or not someone likes you, because different reputations with different NPCs always have different, tangible results. Many players assume that the game is somehow unfinished or that, at least, the writing is sloppy because they lost track of a character and never saw them again. In fact, the choices they made allowed the character in question to become a Karma Houdini, but different choices would've ended in that character being more important and getting an on-screen resolution (of which there are many possibilities, ranging from friendship to backup to Heel Face Turn to execution.) The drawback to this complexity is that if you want to rig the game for a certain, preferred outcome, you're probably going to have to consult a FAQ.
When setting up 5.1 sound in Star Ocean 3, it's done interactively, with Sophia standing in front of Fayt's chair (representing the player). You make her talk by pushing a button, to check that her voice is centred in the sound picture. To start with, she'll loop a few generic 'testing, one two' lines, but if you carry on provoking her, her lines will get increasingly bored and sarcastic. After a good ten minutes, you can make her bored enough to go for a walk around Fayt's chair - but you can still make her talk, obviously allowing you to check the speakers in front and behind you.
In Tales Of Destiny, there is a battle early on against a massively overpowered Leon, which the player is supposed to lose. If it just so happens that you spent a few dozen hours prior to this point level grinding like a crazy person, or are just plain cheating, and manage to defeat Leon, the game still moves on... only the problem is, the game's plot hasn't really started at this point, and it sort of requires Leon to defeat, capture, and then enslave your party. So what happens? You get a short text epilogue that says your party became successful Lens hunters and lived out the rest of their lives with no further incidents. The end.
In Neverwinter Nights 2, if you strip characters of equipment before the final boss fight, where at least one of them will end up committing a Face Heel Turn, Garius will lampshade this and give them some armor himself once they turn to your side.
A similar sequence occurs in Hordes of the Underdark — in a hall of mirrors, looking at the wrong one will force you to fight your shadow. If, for some odd reason, you've unequipped your weapon, the script gives the copy a replacement.
Mask of the Betrayer has one quest where you need to put one party member at the beginning of a Light and Mirrors Puzzle to create a reflection of them at the destination. You can select any party member to stand in the apparatus, each resulting in a uniquely distorted reflection, each with different dialogue.
Also in MotB, there are several subtle dialogue changes throughout the game if your character is a priest of Kelemvor.
In Wild Arms 1, the opening sequence for one character involves entering a password to enter a locked room. He decides to just enter his name as a password to try it (which brings up the character naming screen), and springing a trap. If you name him with the correct password to the door, he says "Wow, it worked! I wonder what happens if I do this, then?" fiddling with the control panel and inevitably setting off that trap.
In Phantasy Star II, the initial confrontation with Neifirst has all the trappings of a Hopeless Boss Fight. With enough Level Grinding and healing items, it's actually possible to win that first confrontation; doing so gets you different dialogue than you get when you take the "normal" path.
In the first area of Fable II, Teresa will call you out on it if you start murdering villagers and points out that you gained absolutely nothing from it (since you don't get experience at this point in the game).
In MARDEK Chapter 2, if you enter Lake Qur and try to go into the tunnel that leads to the Water Temple (an area normally only accessible during Chapter 3), your party member Emela will force you to turn back. Emela remains in your party for nearly the entirety of the game, and the only way to get the Aqualung status effect is to have her cast it on your party. Furthermore, touching any save crystals or getting hit by Earth-elemental attacks will remove the status effect. However, if you have her cast Aqualung on Mardek before exiting Moric's Battleship, after the rest of the party leaves Mardek to his own devices, you can, provided you avoid the aforementioned save crystals and earth damage, take him down to the dock at Lake Qur to jump into the lake. It won't let you jump in. Instead you get this message:
Oh, there's no reason you need to go down there. Yes, I know you set up
Aqualung all cleverly specifically for this, but I assure you, there are no temples
worth exploring down there. Really.
in case you were wondering what was REALLY down there in the 3rd game, it was a Side Quest item for the 3rd game, an orb that you need to collect all of in order to unlock a Bonus Boss, and that's it aside from a few enemies.
Inazuma Eleven 3, and possibly previous games in the series, have a special shoot animation which is only played if the defending team has no available players (not even the goalkeeper) anywhere near the path from the ball/kicker to the goal. Odds are you can complete the entire game without this situation ever coming up, because the goalkeepers' AI isn't stupid.
Inazuma Eleven GO adds two more animations that only occur in highly improbable situations, where a player with an Avatar active either (a) fails to steal the ball from or (b) gets the ball stolen from them, by a player without an active avatar without using a hissatsu technique. Both of these are nearly (but not completely) impossible to pull off.
In Gothic 2, the first quest is to enter the harbour town Khorinis. One can try to get past the guards, but it's also possible to climb the mountains near the city, jump of a cliff into the ocean and swim back to the harbour. A character will comment this as you emerge from the water. Also, the guards will know that you snuck past them.
Final Fantasy Tactics Advance has Silence, a standard status ailment that prevents the user from casting any magic. The in-game description of Silence says the target has lost their voice, thus they cannot cast magic because of it. However, there are several non-magical abilities that requires a voice, such as Advice, Bangaa Cry, and many others. If the unit that has such abilities is under Silence, then they cannot use the said abilities because they lost their voice! Final Fantasy Tactics A2 follows this notion as well.
Both games feature a law system, banning certain actions. Among the laws are those that affect members of specific races. Ritz and Penelo are Humes with access to Viera jobs, but the game designers made sure to include exceptions for them - Hume laws hit them, Viera laws don't. Likewise, Adelle and Frimelda (who get normal Hume jobs, unlike the previous) can equip armor that's normally only available to Viera and Gria (and, of course, Ritz and Penelo.)
In Planescape: Torment you may decide to kill Barr, who takes your money for opening the gate in The Buried Village. But then you find out that he doesn't carry a key - and a short while after that the gate closed itself - and the remaining guards have no idea on how to open it.
And then you realise you can simply bash it open - because it's a rusty gate. This in turn makes the NPCs attack you.
Xenoblade has a unique appearance for everything you can equip, which adds up to each PC's weapons and some half-dozen armor slots, resulting in a LOT of customization. During flashbacks, though, the game will remember what Player Characters were wearing at the time.
In Dragon Age II, during Act 1, Hawke needs to gather a total of 50 gold sovereigns in order to finance the Deep Roads Expedition. However, if the player spends money too often, it is entirely possible for Hawke to not have enough funds to finance the expedition even after all the Act 1 quests have been finished. Fortunately, the dev team came up with an answer for this scenario: A dwarf named Dougal, in a sidequest called "Friends in Low Places," will offer to finance the expedition himself, sparing Hawke the obligation. The catch: Dougal is unscrupulous and if the player takes Dougal up on his proposal, after the expedition is over Dougal will show up at the newly-bought Hawke estate to demand 100 gold sovereigns, double what Dougal financed. Refusing to pay will cause Dougal and a gang of henchmen to attack Hawke later on, but they can easily be killed.
Further into the game, you have to go to the Hanged Man to talk to a drunken guardsman about a recent incident. Most of the dialogue trees from this result in a fight. And, if you do not have Varric or Isabella in your party, they will also be in the Hanged Man. When the fight breaks out, they'll jump into the fight to help you out.
Even though it's not that easy to do in the first place (you'd have to keep running into a force field or wall often enough), it's completely impossible to die in the Tutorial level due to your health meter hitting 0. If your health meter does somehow drop to 0 in Tutorial, the game fills it back up and tells you that you would have died under normal circumstances. It also keeps your Food bar full in Tutorial, so that you don't starve your player before the tutoria's over.
Some of the later dungeons are built largely of solid black walls, the only wall that cannot be phased through with an Ethereal Potion. As a result, said dungeons are much harder to break.
In the sequel, Tomb of the TaskMaker, doors with certain shapes next to them can only be opened if you hold the key matching that shape. You can't even break said doors by phasing through them with an Ethereal Potion, nor knock them down with a Falling Wall scroll.
Given that Radiant Historia is a timey-wimey mess, there are a lot of little obscure things that change based on what events you have or haven't seen. For example, at one point the main character arrives at a fortress, only to find out that the enemy have planted bombs around the place and he has to move over to the other timeline so he can find a way to locate them. However, if you manage to find the bombs without ever seeing the cutscene where they go off, instead of his usual dialogue when disarming them, he wonders why there was a bomb lying around.
Side Scroller
In Yoshis Island, if you stay at the far end of the ledge in Naval Piranha's room, Kamek won't show up, and thus you can take the plant down in one hit. Once you do, Kamek makes a brief (if priceless) appearance and the level ends.
Kamek: OH, MY!!
Simulation Game
Freespace came bundled with FRED (FReespace EDitor), the same development tool the designers used to create the main game's missions. They included a rather amusing response to one attempt at crashing the program. FRED has an autonaming feature: when a new ship is placed, before the user renames it, it is called "1" or "2", or whatever, the number being how many ships had been placed already plus one. It was discovered that attempting to fool FRED's autonamer by renaming a ship to the next ship name in line (for instance, naming a ship "Ulysses 2" and then placing a second Ulysses) would result in the new ship being autonamed "URA Moron 1". For those interested, renaming a ship the next ship in line and renaming a ship "URA Moron 1" results in the next ship being "URA Moron 2" and so on...
In the first mission of Freespace 2, if you don't jump out when the mission is complete, the ships you've been escorting will actually go through the docking procedure with the ship that you're told is coming in for them to dock with. You can watch several minutes of scripted sequence and dialog that pertains to absolutely nothing important.
When the second Sathanas juggernaut destroys the GVD Psamtik in the mission "Straight, No Chaser", , the Sathanas will normally blow the Psamtik away in seconds. However, its beams aren't scripted, just flagged as allowed to fire at will. On the off-chance that they miss enough so that the Psamtik is not immediately obliterated (essentially requiring all but one beam in the first two volleys to miss), the ship's commander and allied command exchange increasingly panicked dialog as the damage starts to pile up. The commander even reports that their jump drive has been destroyed, so you won't wonder why the Psamtik doesn't just take advantage of its luck and retreat while still in one piece.
Similarly, at one point the first Sathanas attacks the GTD Phoenicia. Usually it just gets blown up in the first volley, but if it does survive, the captain basically says "Screw This, I'm Outta Here" and jumps out. Mention of this is made in the debriefing.
The first time you encounter the Shivans, the weapons you're equipped with are not nearly powerful enough to do more than annoy the Shivan ships. The debriefing makes note that no Shivan ships have been destroyed at all, anywhere. If you do manage to administer a Death of a Thousand Cuts to the enemy and blow up one of their ships, the debriefing is altered so that Command congratulates you on proving the new enemy is not invincible.
Occurs very frequently throughout the series. There are numerous ships that can appear in multiple missions, but stop appearing if they are destroyed. Easy to miss since most of these are freighters and transports of no real importance. The most obvious example is the Actium and Lysander.
Fan-made expansions often do this too: Blue Planet has one mission where you lure a destroyer into a trap by disabling some lesser capital ships. The crews of these ships figure out what you're up to and try to warn the destroyer that it's a trap. Even if you destroy their Comm subsystem to prevent this, the ship's crew will manage to jury-rig an emergency transmitter to get the warning off anyway.
Also from Blue Planet, let's say you used cheats to win the Unwinnable by Design mission "Delenda Est". A Sathanas juggernaut called "Mr. Cuddles" will show up to kill you. If you manage to survive that, you get a special debriefing.
And yes, the only way to do that is by cheating. The developers of the mission went so far as to design a custom, extremely difficult AI setting for the reinforcement fighters tested against some of the best players in the fanbase, so don't think you're going to disable some guns and be able to pull off a win.
In The Sims 2, don't think you can get away with screwing around with the social worker if she shows up to take your kids. Most sadistic players who played the first Sims usually boxed the kid or the worker in a room with no doors or the like in order to prevent the kid from being taken away. Trying to pull the same trick off in the sequel? EA gets the last laugh since if the worker can't reach the kid after a certain amount of time, she will teleport the kid to her car! Now imagine that happening in Real Life...
Each expansion in The Sims 2 included big gameplay elements that would have to be accounted for in future expansions, leading to extra features that you would never see if you only had one or two installed.
In University, the college neighborhood has certain restrictions due to time passing differently and students being in their own separate age group with its own game mechanics, which all later expansions had to take into consideration. Students also have teenage voices, meaning the voice actors would have to record lines for all the things adults can do but teenagers cannot.
Nightlife introduced a new aspiration, (Pleasure), which would need to have wants and fears assigned to it in all later expansions.
Open For Business allows players to run their own business, meaning all community lot items in future expansions (such as food stands and pet shops) would need to work when controlled by the player.
Pets cheated a bit; cats and dogs aren't permitted at university, and they can't be taken on vacation. Still, though, they can interact with objects only included in previous and future expansions.
Free Time's hobby system assigns an appropriate hobby to almost EVERY SINGLE OBJECT IN ALL EXPANSIONS.
Don't think you can cheat in the DS version without consequence. Setting back your DS's clock will cause the concierge to accuse you of being a time-traveling witch and aliens will swarm the town. There is no consequence for setting your DS clock forward, other than causing bugs to occur more frequently.
Daylight Savings Time doesn't change your clock, only the timezone information.
This feature does not work if you take the cartridge out at the same time you change the clock!
Many Harvest Moon games have events based on your friendship with certain people. Some of the events involve characters who are in the pool of potential Love Interests; some of the events must be seen if you want to marry them, but some of them are optional. If you see these optional events after you've married them, the dialogue will often be slightly different — in addition to calling you by your nickname, they'll say somewhat different things.
In HM DS, if your Ball item gets lost, Mayor Thomas will return it to you. Your ball can get lost if you so much as sneeze (though you can purposefully ship it or give it to people), but if you specifically throw your ball in the water? Thomas will appear angry and dripping wet, and chide you for being so irresponsible! If he wasn't a champion swimmer, your ball would be lost for good.
What's even more disturbing is that he will also pick up your ball if you leave it on the floor of your house or throw it in the pond in the basement. He breaks into your house to steal your stuff and give it back to you.
When you want to propose to someone, you need to use the Blue Feather, an item that you usually get only once per game. If you show it to an eligible partner, then they'll either agree to marry you or not. If you show it to the other townspeople, then you can get a unique response from EVERY other character in the game, ranging from congratulations on your upcoming engagement, to mistakenly thinking that you're trying to propose to them! This is taken even further in Island of Happiness. There are around 70 extra side villagers that can move to your island. Even though they don't have face graphics, and are all simple Palette Swaps of each other, they'll each have their own special response to the Blue Feather!
Tachyon: The Fringe has a similar setup to Beyond Zork, wherein using cheat codes will result in the main character making fun of you. The fact that the main character is voiced by Bruce Campbell almost makes it worth cheating.
In Evil Genius, secret service agents usually infiltrate the rooms of your underground base via doors, and given enough time, they will hack any door. If they find something incriminating or vital, they'll try to blow it up or take pictures for evidence. If you try and block off incriminating evidence, agents that get close enough will start shooting whatever is in the way, leading to explosions and fires. If you're foolish enough to build a room then brick up the entrance, agents will find (read: make on the spot) secret entrances into the sealed-off portion of your base and carry on with their despicable do-gooding while you are helpless to stop them because the entrance is bricked up. This also works in reverse — locking up an agent into a bricked-up cell only leads to him using another secret passage to get out, and he could end up smack dab in the middle of your power plant. FFFFFFF----
In Uplink, it is possible to find several computer servers which contain Darwinia data files. These files do nothing, but the game makes reference to the Darwinians and their existence several times in the plot. The Revelation virus? Totally made of Darwinians.
In Darwinia, you're cleaning up the last of the mess from Uplink. No, really. It was planned all along that the two games' stories intertwined.
In the Modern Times expansion for Tropico, enacting the "ban social media" edict increases productivity at the expense of liberty. It also disables the game's (sometimes annoying) Facebook and Twitter integration.
X-Plane. Dear god, X-Plane. The simulator for which one of the version update notes mentions that, to increase performance, individual raindrops will only be simulated within a few metres of the plane. And which includes drivers for several actual plane dashboard and radar console hardware simulators..
Sports Game
During the post-game menu in the MLB: The Show series, the PA announcer will refer to the correct, real-life routes on how to exit the stadiums onto nearby freeways and streets for every stadium in the game (for example, where to get to the BART stations from the Oakland Coliseum or how to exit Elysian Way for Dodger Stadium, etc.)
Stealth Based Game
Hitman Blood Money anticipated for "Til Death Do Us Part" that people might disguise themselves as a priest during a wedding. So naturally, there's a bonus cutscene where you can tie the knot for your target.
Running near the jogger in the suburban mission "A New Life" results in him saying, "Nice stride, friend, but you'll ruin your feet in those shoes!"
In Dishonored, the introductory level features a character whose portrait is being painted. Near said character is an item of small monetary value. Much later in the game, the painting is visible in a room; if the protagonist stole the item during the intro, it won't be visible in the painting either, and a character will complain about its absence.
Multiple levels have shrines where the player can have brief encounters with The Outsider. In most of these encounters, he'll offer his thoughts on your current objective, usually describing the person you're on your way to kill. If you avoid the shrine, complete the objective, then backtrack, the Outsider's dialogue changes to reflect it. He even recognizes whether you killed the target or took the non-lethal option.
Survival Horror
Lifeline, the game controlled almost entirely by voice commands, there are quite a few words in Rio's dictionary that you might be surprised by, especially if you didn't actually say them due to the prototypical nature of the game's main feature. Telling her to commit suicide, for example, elicits a response unique to the request. You could also say Rio's voice actor's name (the exact name depending on whether or not it's the Japanese version or the English version) when asked who your girlfriend is for a unique response. She also dislikes it if you swear, ironic considering this is a survival horror game.
Ask her how to open that first door. You'll get an answer that's 100% accurate but useless to you ("Turn the knob!") because you've got a Dualshock2 controller in front of you instead of what's actually in the room your character is in.
In FEAR 2, you start the game in a parking lot. If you shoot at a nearby car for the heck of it, your squadmate tells you to stop ("hey, it's not your car!"). A short while later, you meet with your superior, who asks why you're late; your squadmate says "Becket was busy vandalizing shit". He has different responses if you jump in the fountain ("Becket decided to take a bath in the fountain") or just take a long time doing nothing ("Becket was busy admiring the scenery").
In Call Of Cthulhu Dark Corners Of The Earth, seeing too much disturbing stuff at once will cause Jack to freak out in a number of different ways. One such way is that he'll start muttering to himself in a panic. What he mutters is in direct context to whatever he's seeing that scares him, be it a ghostly girl, a rotting corpse, or a giant monster made of brown acid.
There's a moment where Jack needs to access a ladder locked on a ceiling by shooting its lock. Doing it under the ladder makes it fall on Jack and badly injure him.
Third Person Shooter
Mobile Suit Gundam — Encounters in Space has a truly staggering number of special voice clips for Versus Mode, dependent upon several factors including the characters' partners, their abilities, their mecha, their opponents (as well as their abilities and mecha...). For one particular example, putting Amuro Ray in the Gundam NT-1 will have him start the fight with "This Alexisn't justfor show!" This is also true for the game's Create-A-Characters, who are fully voiced. Making this more impressive is the fact that this is exclusive to Versus Mode, since a vast majority of the combinations involved can't happen at all in the standard story modes.
Similarly, in Dynasty Warriors: Gundam 2, different characters will say different things to pilots they are performing Combo Attacks with. Considering this game has tons and tons of characters to choose from, this leads to a number of characters saying the same thing to some of the pilots, but saying some unexpected things to others. For example, pairing Amuro Ray with Heero Yuy causes Amuro to say "You're a good shot!" and Heero to respond "Not as good as you!". Additionally, placing a Universal Century pilot, such as Seabook Arno, into a mobile suit other than their main model (the F91, in this case) will cause them to comment on the fact that they're piloting an antique (any mobile suit from an earlier era) or how advanced the suit is (for mobile suits created after their relevant series/movie). Another example happens when you put Char Aznable (CCA) in the Zaku II (Char Custom) or Hyaku Shiki (quite possibly also Char's Gelgoog, Z'Gok, and the Zeong). In this case, he wil say "This Mobile Suit... It brings back old memories..."
This returns in Dynasty Warriors: Gundam 3. Less obvious combination SP attack quotes include Banagher Links and Domon Kasshu, who both call out to their loved ones, Audrey and Rain, respectively. Kou and Jerid have one in which the latter will demandingly call out to Kou as 'Ensign' and tell him to follow his orders. This pull-of-rank irritates Kou, who tells Jerid he can't boss him around.
Having Kira Yamato pilot the Infinity+1 Sword unit, Knight Gundam, will have him sometimes begin a mission saying that he can do some real good with his new sword, before shouting the Gundam's name.
The first non-prologue area of Max Payne 2 involves the investigation of a warehouse area. One of the private cleaners of the site insists on letting you in and showing you to the main storage area, at which point he and several of his underlings ambush you and the real violence begins... unless, of course, you already know what's going to happen. You can simply kill him upon your first encounter, causing the monologuing protagonist to say 'The perp's disguise didn't fool me, he was leading me into a trap' instead.
All over the place, actually. Any stage that allows you to roam around in one way or another supplies you with many little sweets, some dialogue, and some actual animations:
Just for instance, in Payne's or Corcoran's apartment complexes during their respective shootouts, if you knock or try to open any other apartment doors that you aren't supposed to, people inside will call out to you things along the lines of "Get lost!", "The cops are on their way!", and "Ooooh, ooooh yeah!", thus averting the mistake other games usually commit.
Or the police station: There are, of course, a man making a statement on how his wife and her lover killed themselves in his house and THEN framed him for the murder or the stripper who receives threats from her video shooter-addicted boyfriend after she threw his TV out of the window. Then there are several areas you will probably never have to go during the game, such as the traffic control centre and the recreation room. In the former, you can listen to the officer in charge giving directions and confirming orders, but in the latter, you see two cops watching TV. If you get between them and the TV, they will shout at you to get out of the way and try to lean around you. If you actually turn off the TV, they will call you an asshole and turn it on again with a remote.
In the third game, Max can carry one large rifle or shotgun and two smaller weapons. Max will realistically carry his longarm in his off hand due to the lack of a sling, even during cutscenes. And if Max needs to go Guns Akimbo, he has to drop the long gun. The game even edits cutscenes to take account of whether or not Max entered the scene carrying a rifle and has to put it down or have it taken.
In Red Dead Redemption, you can whistle to call your horse to you. If you do this while a dog is nearby, *
there is usually one or two roaming around in the settlements
it will follow you.
You can also lasso deer, elk, goats, and rams, but you can't ride them.
You can jump off from a second-story balcony or window onto your horse and ride it out of town.
The trains will stop at a junction to wait for another to pass through before going themselves.
Speaking of trains, there is an achievement for dropping a hog-tied woman in the way of one.
John (and subsequently Jack) has multiple unique battle taunts for each of the twenty (and completely optional) bounty targets.
Jack also has a full set of dialog recorded for each Stranger mission if you wait until the endgame to complete them. The one exception to this is I Know You. If you somehow manage to not do this mission before John dies, it won't count against getting a 100% Completion achievement/trophy.
Turn Based Strategy
Disgaea 2. Try sending multiple people into the Dark Court at once, for example...
A lot of the subtler game mechanics in the Disgaea series seem to be built around this trope as well. Throwing enemies into your base panel, for example. (Save first.)
List of characters that can be hacked intoFire Emblem: Path Of Radiance. The fact that one of these characters shares a name with a character from Radiant Dawn is probably just a coincidence, as the two have different classes. The fact that Zelgius and the Black Knight have the exact same affinity, weapon ranks, and growth rate? Uh... not so much so. Yes, the Dev Team Thinks of Everything, including putting in spoilers for the sequel.
The dev team didn't get sloppy in the sequel, either, as they included many scenes of dialogue which are incredibly hard to see, like characters on opposing armies having a unique conversation before they battle where it's incredibly hard to get them to fight (like Micaiah and Soren, where the former cannot cross a specific line which she must defend and the latter is an NPC which rarely moves) and the Black Knight having a unique death quote if he dies on the chapter where you control him and none of the enemies can kill him.
For that matter, in Path of Radiance, you get a lot of variance in scenes depending on whether or not certain characters died. (Even some Support Conversations change to reflect who's alive and who isn't, most notable being Makalov and Astrid)
Similarly, Sacred Stones has the image and stats for Nergal, the Big Bad of the previous game. Even though they take place in completely different worlds.
In Rekka no Ken's penultimate level, The Value Of Life (32x in Hector's Story, isn't in Eliwood's), the mission is to kill the Magic Seal Kishuna, whose chamber is closed off by a door and who summons reinforcements when said door is opened. Using the Warp Staff to send a unit into Kishuna's room on turn 1? Not such a great idea, or if you do, you'd better be prepared to go right after him rather than wasting time so your other units can pick up the treasures in the level. Sending a unit to the space directly above the door while it is still closed causes it to not only open on its own, but four Berserkers that wouldn't otherwise be in the level show up as reinforcements. *
The Snipers and Generals that populate the level in Normal Mode are replaced with Berserkers in Hard Mode, but using the Warp Staff is the only way to make Berserkers appear in that stage on Normal.
Also, in some Fire Emblem titles, there are levels in which there is a door which opens automatically after a specific number of turns, usually by an NPC. Under normal circumstances at the points in the game which they occur, it is effectively impossible to get to the door before it automatically opens. However, if the player somehow manages to reach the door and open it themselves, an otherwise inaccessible cutscene is displayed to accommodate the situation. Chapter 16 in Rekka no Ken is an example of this.
At the end of the prologue in Shadow Dragon, you must choose a unit to use as a sacrifical decoy so that the rest may escape. It is possible to choose Marth, even though the decoy will be Killed Off for Real and Marth dying ends the game. There is a specific cutscene for this scenario.
Related: There is actually a bit of Gameplay and Story Integration around this subject, too. If you do play the prologue, and send a character to be Killed Off for Real, you can't use them. Later in the game, you are given one item called the Aum staff, that lets you resurrect one character. Since most players go for 100% survival, a lot of players' first instinct was to use it on the sacrifice...but it's not an option. However, "New Mystery of the Emblem" brings about a very clever explanation: Frey was indeed the canon sacrifice; however, he is alive and well in New Mystery. Supports with the player reveal that he was the sacrifice, but instead of being killed, he was beaten up and left for dead, but was rescued by some civilians, and survived with a scar and memory loss. So in summary, you can't use the Aum staff on the Sacrifice, because they never actually died!
There have been a few occasions in which a boss who you are not supposed to beat actually has dialogue or a situation on what happens if you do manage to beat them.
In Genealogy of the Holy War, the Final Boss appears on a map. You actually can beat the boss, to which they'll respond with "Playtime is over — I'm going home."
You are told not to kill Fargus in Rekka no Ken. However, you actually can attack him (Which isn't recommended, seeing how powerful he is) and the game takes into consideration what happens if you do kill him — you get a Game Over.
In Radiant Dawn, one chapter has Lekain on the map. While he is supposed to flee when someone shows up, you actually can get over to him and beat him, causing a scene to play where he retreats.
If you use an Action Replay to boost the experience gained in Disgaea DS, the game will adapt the characters leveled up in this fashion so that they need to more than double their total EXP gained just to go up one more level — essentially forcing you to keep using that cheat just to level up at the normal rate. Of course, by the time it figures it out (which varies from character to character), you could already have your characters' levels in the 4000s... (usually, it figures it out by around 2300 or so.)
The Super Robot Wars OG games have sets of dialog for any character piloting any mech (except in cases where characters have their own specific, exclusive one), occasionally with some humorousresults.
Additionally, an early scenario in OG2 has the player, with only four units, being ambushed by three boss units. However, with persistence, a crazy player CAN beat them, resulting in a Breaking the Fourth Wall moment and rewarding the player with various powerful items.
Super Robot Wars Z has many such instances. For example, The Big O is a ground unit which has melee attacks which do not work against aerial opponents, but if you attach a "Minovsky Drive" which allows it to fly and use these attacks, you see that they have specialized, completely unique animations for mid-air use. Another one is an Easter Egg special dialog that can be found if you reduce the penultimate boss' HP to exactly 1 point, where it goes on a rather lengthy rambling session. Lampshades the whole idea with the ground-only Iron Gear (WM)'s punch attack — if it's given some way to attack aerial foes, it won't use its boosters to jump up. Rather, it just kinda... floats up, perfectly in key with its source.
It's possible, with a lot of time, care, and planning ahead, to run out of fuel on every unit during the first campaign mission in Advance Wars 2 - doing this causes Nell to yell at you and tell you to Yield so you can start over.
Wide Open Sandbox
In Bully, English class requires you to play a mini-game where you must unscramble letters to form as many words as you can. One level includes the letters H, I, S, and T. If you spell a certain word using those four letters, it doesn't count, and the teacher just gives an amused response.
In the GameCube version of Animal Crossing, your villagers complain if you send them gibberish letters because the game was designed to look for certain things... which means that you can still write gibberish so long as you use proper spacing and punctuation. However, writing a letter in French could result in the villager's return letter reading something along the lines of "Bonjour! Sorry, my French isn't very good..."
If you reset the game enough times, Mr. Resetti will force you to write a letter of apology. If the player doesn't write it exactly how he dictates, he'll force you to do it again. However, writing something like "Hell no" or "I hate you" will cause Mr. Resetti to freak out.
If you use Detective Mode while fighting The Joker, you'll find out far earlier than you're supposed to find out that he has no bones, and is therefore actually Clayface.
The enemy chatter will change depending on who you're controlling. For example, as Robin, the mooks will mock the player for being a kid, and Batman's not around to help him.
Early on in the game, there is a Riddler trophy in a cage connected to two question marks. You're SUPPOSED to wait until you get a certain item later in the game to beat it, but its actually possible to get it immediately by standing on the target, using a quick batarang to hit the first target, then quickly switching to the remote controlled batarang, throwing it, boosting it to get it past the bars, then braking it and waiting for the second question mark to light up. The Riddler will then complain at you for cheating.
It's entirely possible, using a glitch involving standing on a ledge and continually throwing Freeze Grenades on end, to glitch yourself up high enough in the game world to glide over the barrier surrounding Arkham City. Using this method, you can actually fly around and explore the rest of Gotham City. Yes, that big skyline you see in the background throughout the game was actually constructed and was fully detailed by Rocksteady (although the buildings are all hollow inside). You can glide around and watch cars passing back and forth on the bridges, fly to Arkham Asylum (which is also present, although significantly scaled down) and fly up high and see that the game world goes much further than just Arkham City. Most players won't even glimpse most of it (and it will glitch your save file out if you haven't backed it up elsewhere), but the fact that they put all this work into something most players would never see up close is nothing short of incredible.
When you finally confront Hugo Strange at the top of his tower, take out all his guards, and prepare to open the last door separating the two of you, Strange stands in front of the door calmly taunting you ("I am better than you, Wayne.") However, your detective vision reveals Strange's pulse is beating a little faster than normal. He's actually a little nervous about being face-to-face with a pissed-off Batman. Go figure...
If you activate one of Harley's mannequins in the steel mill, you can hear random comments. If you activate it after the end of the game, you will hear her crying. If Batman is killed on the Joker's turf during the epilogue, Harley will say "You were supposed to save Mistah J, Batbrain!" to you.
When The Joker does his Break Them By Talking on your second trip through the steel mill, notice that the cameraman coughs and shakes the camera during the broadcast. Because it's the real Joker filming it, and he's not cured.
One notable aversion: The Mad Hatter interlude is a side mission and hence can be done after the main mission is complete. However, the post-hypnotic suggestion still says that a cure has been dropped. Batman still injects himself with it, despite already being cured, and in the cut scene, the Mad Hatter talks about Strange as if he was still alive.
Depending on whether you finish the Bane sidequest before or after you beat the game, his hideout is ambushed either by TYGER guards who want to confiscate the TITAN or a group of Joker mooks who want to either use it for themselves to have a chance of survival now that their boss is gone or just take it back since it was Joker's to begin with.
If you manage to destroy all of the Tyger cameras before Protocol 10, one of the Tyger guards will mention over the radio that they are completely blind.
Also, they clearly figured out the question of how Mr. Freeze could get over to his wife after you tell him where she is. After doing so, you will find behind the GCPD a long ice walkway in the water leading to the warehouse.
In the New Game Plus, during the first Riddler room, you can bypass most of it by using the line launcher. Riddler will remark on it, and mock you for cheating.
He'll also do so if you just choose to run across parts of the electrified floor to skip most of it.
In the beginning of the game, after beating up Penguin's mooks, the player could just leave Penguin alone without knocking him out and go up the ladder. The Dev team anticipated this possibility, so they had Penguin say something specifically for that occasion, which is where he taunts Bruce Wayne about him always knowing that Wayne was a coward.
If the player decides to stick around during the "countdown" on the clock tower, Joker will end up summing up the final events of the game before telling Batman that he really needs to get out of there.
Batman can find and destroy five out of the six Titan containers he needs to destroy for Bane's sidequest before ever even speaking to Bane. His dialogue will change to reflect this. The reason he can't destroy the sixth one is because doing so would give Bane no time to find his 6, and thus the Titan Container by Joker's hideout does not appear until after you talk to Bane.
Catwoman has a surprising number of lines that play in specific circumstances. You can go back during the epilogue and visit any of the villains that are locked up or incapacitated (Bane, Mad Hatter, Ivy, etc.), where you will get special one-off conversations where they ask her to release them (which she refuses every time, for various reasons). In addition, she will have a unique conversation with Calendar Man if you visit him, where she says she won't release him after "what happened with the Falcones" (a likely reference to Dark Victory).
Intentionally screwing up Zsasz's sidequest will lead to extra phone calls past the ones in which Zsasz describes his first kill. Failing both of the extra calls as well will finally make the game automatically find his hideout for you.
Non-video game examples:
Arcade Game
The pinball game Indiana Jones: The Pinball Adventure features a sinkhole chute that is guarded by three targets. Normally the sinkhole is accessable only when the targets are stuck and dropped out of play, revealing access. Because pinball games are physical, it is possible to slip by without striking the targets. The character Short Round will cry out, "you cheat, Dr. Jones!" and awards bonus points.
There is also a bonus section where you are supposed to hit various targets to fight against a swordsman displayed on the screen. However, if you remember that the ball launcher is designed like a gun trigger, you can indeed follow in Dr. Jones' footsteps and just shoot him.
The same could be done on The Shadow pinball machine, where you could make a pinball shot to defeat attacking Mongols, or just shoot them. This added a tactical dimension, as shooting the Mongol awarded far fewer points, but certain features were not accessible during the Mongol Attack, meaning that skipping it could avoid you being frozen out of the feature you actually wanted.
Pinball games in general include many of these, to protect against the game ending up in a situation the physical hardware can't resolve:
On all Pinball machines, if nothing seems to have happened on the playfield for a while and no flipper has been touched, the game reasons that the ball is stuck and starts randomly firing off all of the kickers and features on the table to attempt to unstick it. Some games also have quotes or special displays at this point (Funhouse, for example, would say "Where did you go now?")
Likewise, Williams Pinball machines were famous for their ability to detect when a physical part of the machine had failed and compensate for it by modifying the rules of the game. So if a sensor hadn't triggered for a while, the game would substitute another sensor along the same rail or shot. This was an incredibly useful feature for arcade owners, and the source of some annoyance that machines from other manufacturers didn't do this (this wasn't their fault, though - Williams patented it.)
In "The Addams Family", if a ball enters the Vault while the Bookcase barrier is still supposed to be blocking it, the game proceeds as if the vault had been open but Gomez's quote is changed to "Dirty pool, old man — I like it!".
In "Funhouse", Rudy's mouth is normally only a valid shot when it is locked open as he's asleep, but incidentally shooting the ball into his mouth while he's speaking causes him to spit it out, shouting "You big cheeseburger!".
In "Whitewater", if the player shoots the ball weakly around the orbit, causing it to roll backwards through the No Way Out lock mechanism and back onto the lower playfield, Willie shouts "You found the secret passage!" and a bonus is awarded.
On the Star Trek: The Next Generation pinball game, if you guttered a ball or timed out during a Mission Mode without scoring points, you would get a minimum point bonus while hearing Data say, "Had you propelled the ball along the proper trajectory, you would have been rewarded." If you trigger both flippers at once midway through Data's line, you receive additional points, and Captain Picard cuts him off with, "Thank you, Mister Data."
Operating Systems
Although not a game, the Windows CE emulator in Virtual PC was clearly programmed by someone who understands bored techie tendencies. Attempting to set up a recursive emulation results in an error with the text "You just had to try, didn't you?" This may be considered erroneous behavior, since it means the emulator doesn't perfectly recreate the environment, but on the other hand, dicking around with recursion is pretty erroneous to begin with.
The Unix cal command prints calendars. If you type cal 9 1752 you get the calendar for September 1752. The 14th follows the 2nd because England converted from the Julian to the Gregorian calendar at that time.
Tabletop Games
GURPS tends to evoke this, especially when reading the more specific supplements. The Space book, in particular, seems to cover EVERY possible trope related to space. The alien creation rules contain everything from trophic level to biological symmetry.
The martial arts supplement gives 58 different real-world combat styles (not counting differentiation by era, and all forms of Kung-Fu are considered one style) plus another five they made up.
Dungeon Fantasy 8: Treasure Tables gives listings for spices, toys, furniture, perfumes, paintings, and containers. It even gives guidelines based around culturally distinctive styles and additional trappings that the designer calculated to create several trillion variations. Dungeon Fantasy 2: Dungeons gives detailed rules regarding harvesting organs, teeth, and natural poisons of dead monsters and what bits of scrap taken from dungeon trappings will sell for back in town. Also, want to sell stories of your adventure to bards? There's rules for that as well. Other material involving the Dungeon Fantasy lines are templates for playing Justicars (city watchmen and kings' guardsmen), Sages, Ninjas, Innkeepers and Mystic Knights.
Spaceships is probably the only place in an RPG book (outside of Traveller) that you can find relativistic equations. Fortunately, they're very much optional.
Super-extra-lucky-rare tabletop version from Vampire: The Requiem: In the previous incarnation of the game, some Disciplines were notoriously easy to ignore. To hammer home that this iteration is more ruthless and harder to cheese, the developer's state that that using the Dominate Discipline always requires eye contact, and if a character were to try to ignore this rule by wearing sunglasses, said Ventrue player is free to laugh at the n00b's incompetence.
V20 backports these rules to Vampire The Masquerade, and further notes that since the need for eye contact is symbolic rather than literal, even removing your eyes doesn't render you immune to eye contact — it just makes it much easier to avoid it.
On a more practical note, the dev team was kind enough to supply the likely effects massive pressure differences would have on vampires. In space.
The 'Armory' books list (among numerous other Improvised Weapons), the effects when using a belt sander or post-hole digger as weapons.
In the old World of Darkness, a rulebook gave the stats for using a chainsaw as a weapon. Not so unusual, except it also included the moral and psychological repercussions of using a chainsaw on another flesh-and-blood person.
The number of unusual and obviously dangerous substances that the Dungeons & Dragons writers stat out the effects of touching, eating, drinking, or doing something borderline suicidal with approaches the infinite.
Toys
Omega Supreme's toy in Transformers Energon has three parts: A giant battleship, a huge crane, and a small robot which formed the head. When in combined mode, Omega Supreme's body (Made of the crane and the battleship) have a head of sorts that can be raised when the actual head unit isn't attached. Reason? To actually give the big guy a head if one loses the headmaster robot.
Web Animation
There is a Strong Bad Email in which Strong Bad buys a new comfortable chair to check his emails with, but the chair itself is huge and covers up most of the computer screen. Strong Bad proceeds to respond to an email by taking off his wrestling mask and showing a picture of his parents on the computer screen, but both are obscured by the chair. If one attempts to use a flash decompiler to remove the chair, Strong Bad's head will be missing and the picture will have the message "nice try dodongo!" on it.
Web Comics
xkcd had an interesting April Fool's day in 2010, which can be found here.
Especially funny if you type in a certain four letter word. The response? I have a headache.
Try entering 'Help', 'Sleep', or 'Kill'.
Or 'Next to Last'.
Followed by 'Enable time travel'.
'Cheat', and of course, 'Quit'.
When you type 'look' you have exits of "West" and "South". Going "West" repeatedly will report interesting statements about each room you visit. It's the lyrics to the Chorus of "Go West" by The Village People. Hilarious. Going south will result in being eaten by a grue, unless you thought to type "light lamp" first.
And if you type 'go east' after going 'west' once, you get: "You are at a computer using unixkcd."
Entering 'xyzzy' will respond "Nothing happens", rather than a generic "must be roto".
"find" also works; the game asks you what you want to find, and suggests "kitten."
If you search for the afforementioned kitten, the console searches for a popular flash Metroidvania called Robot wants Kitty.
"make love" results in the predictable "I put on my robe and wizard hat." This itself is a reference to the TOPS-10 operating system, which used the "make" command for the creation of a file. When "make love" was inputted, the OS would respond with "not war?" before creating the file.
The comic's 2012 April Fool's gimmick also qualifies. The strip posted that day, "Umwelt" *
German for "environment"; it's an idea from semiotics. See the alt-text or That Other Wiki for more.
, came in dozens of different variations; which one you see depends on your "perspective", i.e. location, browser, window size, etc. How extensively did Randall do this? There's a specific comic for Netscape Navigator.
xkcd's back at it again with this strip. Click and drag and drag and drag and drag...
According to the alt text on comic #1189, the US Census Bureau has defined the "US Census Bureau Solar System statistical boundary." If only this were actually true.
8-Bit Theater had an in-universe example with Black Mage attempting to copy a spell that Sarda used to rewrite reality according to his will, deducing it to be a "Rewrite Reality According to My Will" spell. It turns out to be a "Rewrite Reality According to Sarda's Will" spell instead.
In fact, Sarda casts all his spells this way, at least when he's around Black Mage. When BM copies an incredibly painful spell that Sarda has just used on him, he discovers that it's not a "make target vomit out his intestines" spell, it's a "make Black Mage vomit out his intestines" spell.
When Sarda casts a spell that hurts you, you learn to cast a spell that hurts you.
Web Original
Akinator knows pretty much every single person or character that anyone in the world even slightly cares about. It's not the "Dev Team", per se, but the contributions of millions of players that make up its bottomless knowledge. He also catches onto your attempts to con him — try to click "No" every time and the answer will be "Someone who kept clicking on No to see what happens".
Twitter has a 140 character limit. If you try and make a tweet with more characters and click at the nick of time, it will read "Your tweet was over 140 characters. You'll have to be more clever".
Is X a Prime Number? tells the viewer to stop wasting bandwidth whenever they look up an even number. Although "http://www.is.0.aprimenumber.com" just leads to the main site, it does have a unique message for zero, which can be found at "http://www.is.00.aprimenumber.com". Negative numbers will redirect you to the creator's main website, as will any string with an underscore in it. Finally, entering letters produces the message "I need a real number, yo."
Should you enter 42, it will tell you that it's not a prime number, but it is the Answer. If you enter 666, it'll tell you "No. And you're not the first person to ask. You little devils."
Pokécheck is a website that, among other uses, can check the legitimacy of any Pokémon uploaded to it. It takes everything into account when checking to see whether or not a Pokémon was likely edited or created using an external device. Unusual stat totals? It's got that covered. An obscure glitch that only affects five species? Of course. And if a Pokémon has a Trainer ID of 00666 or some equally unlikely number, it displays the message "Suspicious trainer I Ds." Good luck finding a way to get past it.
General
IBM RnD, according to Prof Moriarty speaking on the Sixty Symbols YouTube channel. "You read [one of their research papers] and questions arise. Then you go back and see 'oh, right, they've done that as well'. And then you think 'well maybe this', but every single question is covered."
PNG files always begin with the following bytes (in hexadecimal): 89 50 4E 47 0D 0A 1A 0A. Seems random, but it's actually carefully constructed to prevent against as many potential problems as possible.
89 makes sure the file is interpreted with 8-bit data, and protects against file transfers that would convert it to 7-bit data.
50 4E 47 is the code for "PNG" so that image programs can identify the file. It's also human-readable, in case the file is opened in a text editor accidentally.
0D 0A is a CRLF (DOS-style line ending), and protects against file transfers that translate CRLFs to LFs (Unix-style line endings).
1A stops the file from being displayed as text under MS-DOS and similar systems.
0A is an LF, and protects against file transfers that translate LFs to CRLFs.
In short, the PNG file format automatically protects against 90% of all possible file errors in the first eight bytes.
Similarly, the custom content in Spore are entirely in PNG format. Yes. A picture file. This allows saving pictures from the sporepedia website and moving into the creation folder and detected as Spore creation complete with information and tags, even when the computer is offline while playing Spore.
The PNG format specifies that you can have any "tag" you want in an image file. There are a number of required tags for image data, but PNG parsers are required to ignore tags they don't understand. So the Spore team could have made their own tag for the creature data, but they didn't. Instead, they encoded the creature data in the alpha channel of pixels surrounding the creature's mugshot. Talk about taking the hard route...
This trick was also used in The Sims 3 for iOS devices, which requires you to do a screenshot of the intended character at a designated export screen. Unfortunately, due to the differences imposed by the compatibility layer when running iPhone software on an iPad, the scheme fell flat on its face if exporting the character is attempted on an iPad.
Detroit's Comerica Park, home of the Tigers, has a statue garden of their legendary players in the deep center field stands. One of them is memoralized with his glove up and open. The artist took the time to fill the interior of the glove with small nails, so that on the one-in-a-million chance that a home run is hit into the glove, the statue will "catch" it.
The iPhone app Siri is an "intelligent personal assistant" that can look up information via voice commands. It also has smart-ass responses to a number of questions, requests, or commands, like "How much wood would a woodchuck chuck if a woodchuck could chuck wood?" ("That depends on if we are talking about an African woodchuck or a European woodchuck."), "What are you wearing?" ("Aluminosilicate glass and stainless steel. Nice, huh?") and "Talk dirty to me" ("The floor needs vacuuming.")
Some email processors will, if you write the words "Attached is/are..." without giving an attachment, ask you if you want to attach anything before they send it. This is quite useful (or annoying if you're a high school student trying to use an excuse other than "the dog ate it").
The free music program Spotify plays commercials between songs. If you mute your speakers during these, the commercial pauses until you unmute the sound.
Google Maps will give driving directions to places on different continents, including at necessary places "Sail across [insert body of water]".
At one point Google Maps would respond for directions to Mordor with a custom error stating "One does not simply walk into Mordor", but sadly that has been removed.
Still there, you have to enter "The Shire" and "Mordor" and select walking directions.
The page quote comes from the TV Series The Big Bang Theory: Basically, Sheldon wants to learn how to drive on a simulator in order to get practice on it before getting a driver's license. Howard Wolowitz modified an armored vehicle simulator he developed for the military into a car simulator so Sheldon could practice driving. Of course, as the quote indicates, he does terribly on the simulator, and eventually crashes into a pet shop (presumably also running over some of the dogs and cats). Sheldon then tells Leonard to remind him to thank Wolowitz for developing the software, as its graphics were amazingly detailed.
