Selective Memory is when the game denies the player knowledge the Player Character has, should logically have, or should be able to acquire effortlessly and instantly.
That map of the world that the Player Character got from their uncle before heading out to save the planet? Features the Doomed Hometown and a whole lot of blank indicating everywhere you haven't been to yet. The soldier who joins the party and suggests you go to the Hub City to ask the king for help? Forget about asking them for directions. You come to the Hidden Elf Village and the White Magician Girl wants you to talk to her sister? Talk to Everyone until you find her yourself.
When used on background information, this can be a way of putting a certain distance between the player and the player's character. It can also be a storytelling device that allows the player to discover certain facts about the character. Coupled with Schrödinger's Gun, it can be an interesting way for the player to choose what the player character did some time in the past.
- In the opening scenes of the original Pokémon games, the Professor seemingly forgets the name of his grandson and asks you to effectively give him a new name.
- This is often abused to make funny videos, where someone names him something along the lines of "idiot" or "stupid" and spends a long time laughing as everyone keeps calling him "idiot".
- In Arcanum: Of Steamworks & Magick Obscura, the player begins the game on the site of a zeppelin crash of which he/she was the sole survivor. Initially, the world map consist of an outline of the continent on which the story takes place and the crash site and a nearby village being marked. Though the player boarded the zeppelin before the beginning of the game in the second largest city in the game world and it was supposed to go to the largest one, which is located at the mouth of a major river clearly marked on the world map, they are not marked on the map initially and you have to aquire the knowledge in-game.
- In the same game, there is a quest in which you must ask an elf for the location of elven capital Quintarra, a literal Hidden Elf Village. If the player character is an elf, he will find it odd that you do not already know the location. One has to justify it by claiming to be from a different continent.
- In one level in Super Mario Sunshine, Mario is tasked with locating a Yoshi egg, hatching it, and using the Yoshi to power up a merry-go-round. One expository NPC informs Mario that he has just seen an egg on the island, which is used to suggest to the player what to do next, but he leaves it at that.
- Final Fantasy IX featured a card game with vague rules which are not particularly explained to the player. Justified in that nobody you talk to know the rules either, and you can only pick up the rules from people's suppositions about them. These people are otherwise avid players, but they only know half of one rule each... Fortunately, none of the rules matter much. The outcome of each game is more or less random, and the few rewards with an actual use you can get out of it are easily gotten elsewhere...including one of the very few cards you can get outside of the treasure hunt sidequest that actually has an use beyond using it in the card game itself.
- A full explanation of the rules was eventually provided...in the manual for Final Fantasy XI.
- Inverted to very great effect in BioShock, where at the beginning of the game the player must perform several actions that seem initially to stretch credibility (such as calmly sticking a massive and unfamiliar needle in his arm with no prompting whatsoever), because for someone with no knowledge of the city of Rapture they make little sense. In the plot twist at the climax of the game's second act, though, it is revealed that the character did know about these things, but that the memories had been suppressed, thereby using the player's own innocent actions to simulate unconscious behaviour choices on the character's part.
- In Final Fantasy IV, Rydia shows up during a Boss Battle. After the battle, she tells you what happened when she was eaten by Leviathan—it actually took her to the land of Summoned Monsters. While this is good and all, not once will Rydia tell you how she got to where you are, leading one to wonder HOW she got out, since as the player begins wandering around, they will find the passage leading there on a small island in the underworld, surrounded by lava. It isn't until you've ventured into said cave that Rydia mentions that this is where she was.
- Both averted impressively and used shamelessly at the same time in Knights of the Old Republic II: other characters will ask leading questions about the PC's past, allowing the player to learn the details by reading their own dialog options. In a few cases, the player gets to pick from mutually-exclusive options, and the answer actually determines what happened. However, everyone still talks around the specifics of one important event in order to keep it a revelation to the player, even though the PC should know more about it than anyone else.
- Lampshaded, subverted, and abused to no end in the Nintendo DS visual novel Time Hollow, in which Ethan (you) and a few other key characters are expected to have a "perfectly normal memory" immediately after any given alteration of the past, regardless of who changed the past, when it was, and how it was changed.
- Inverted in a New Game Plus joke ending: Ethan will already know the plot of the game, since he's the player character, and as such he's played through it before. This fits with the time-travel theme of the game.
- Averted and played with in Baten Kaitos, which helps set up one of the twists in the plot. In the game, you play not as the main character (Kalas), but as a spirit guide that helps the main character. At the beginning of the game, you of course start off knowing nothing—and Kalas expresses concern over your amnesia. But why do you have amnesia? Kalas is siding with the villain, and the spirit guide began to express concern over his plans and tried to argue against it. Worried that the spirit guide would leave if the disagreement continued, Kalas and the villain cast a spell to take away the spirit's memories.
- In Infinite Undiscovery, you start out with zero information about the area you're in. That's OK, maybe the protagonist isn't from around there... But he's never alone, there are always others in the party, locals from all the featured areas and well-traveled people. The game even gives you the ability to talk with your party members at any time, so why can't you just ask them for directions when you're lost?
- Used in Grand Theft Auto III to some extent. While the game is generally helpful in using an in-game map with directions with places you need to go, there's no way to see the large map. This makes plotting routes of long distances extremely difficult, and makes any mission that doesn't give you markers very difficult to figure out. To wit, one mission involves stealing a Yardie car in Newport, without bothering to explain what a Yardie is, what a Yardie car looks like, or what the boundaries of Newport are aside from being "north".
- Fire Emblem:
- Fire Emblem: Path of Radiance. Oh, the main character picked up the Infinity +1 Sword a few chapters into the game? And he's had it all this time? And he still refuses to use it until much later?
- In Fire Emblem: Radiant Dawn from the same sub-series, said sword is conspicuously missing from said character's inventory. Later on, the player gets caught up with an explanation that the sword was handed over to Begnion after the events of the first game.
- Cole, the player character of inFamous claims to know the Empire City sewers like the back of his hand. This does not mean the player gets a map or any other indicator of Cole's memory of them.
- Inverted in Chariot of the Dogs. If Sam and Max mention time travel to Superball, he deletes their short-term memory. They completely forget about it, yet you retaining this knowledge lets you solve a puzzle later on.
- In the text adventure Byzantine Perspective, you play a thief breaking into an art museum. The entire gimmick of the game is based on the fact that you, the player character somehow seem to have forgotten that you are wearing virtual reality goggles, meaning that the room you see is about three rooms over from the one you are actually standing in. The way the game expects you to figure this out is by realizing that you can't read a piece of paper that's in your inventory, then dropping the paper on the ground and walking into the next room, where you will now see the paper lying on the ground and you can finally read it.
- Lampshaded in Star Control 3. Your PC was directly responsible for and involved in most of the major events of Star Control II. You can still go through and ask the leaders of the different species all about their history, including things you should already know about. At one point, when you ask the Vux leader, he says, "You know our history! You were there!" before launching into a detailed explanation of their history.
- In the Fate/stay night Heaven's Feel route, one of the climactic battles involves a plan where Shirou needs to use his very limited number of remaining projections at a very specific point in the fight. When the fight starts to look like it's going south you need to have faith in your partner that they can endure long enough to get to that specific point for the plan to come together, if you use a projection to help them at that point you won't have enough remaining for the full plan and can't get the good ending. Which is all well and good... only Shirou (the person you're playing as) never explains his plan on screen (so you don't know what it is before hand) so you have no idea you're supposed to be fighting conservatively your first time through.
- Played to award-winning effect in the Interactive Fiction game Spider and Web. The game is quite forward about the fact that your character knows more than you do; they are strapped to a mind-reading device, and most of what you do in the game is in the flashback it causes. To advance past this stage, you need to guess what exactly your character is trying to hide from their interrogator.
- Fallout: New Vegas only gives the player brief snippets about the Courier's past, as the only sources of information are NPC conversation and your own dialogue, which rarely touches upon your life before the events of the game. Not only is the player expected to fill in their character's past with their own imagination, the Courier also receives two gunshots to the head during the game's opening cinematic, which could reasonably cause gaps in the character's memory.
- In Marvel Ultimate Alliance it's entirely possible to ask questions like "what is SHIELD," or "who is Namor," even though you're playing as characters who should know these these things.
- Dungeons & Dragons 3.5 was like this with a literal interpretation of some of the rules. For example, a Dwarf (a race that is known for fighting giants so frequently they gain racial bonuses against giants due to special training) Ranger with giants as their favored enemy would not know that trolls, a very common and dangerous type of giant, can regenerate from injury unless you Kill It with Fire unless the player succeeds a Knowledge skill roll. And since Knowledge checks can't be made untrained and most of the time a player has priorities with other skills, this meant that a character could easily not know anything about common enemies that everyone who grew up in that world should. 4th edition made this even worse with its "monster lore" rolls. While fine for some of the rarer and more esoteric monsters or their weaknesses, it meant that you often had to roll to know things so blindingly obvious that literally every character should know or figure them out intuitively. Infamously, you needed a decent roll to know that Cave Bears are bears that live in caves, and they don't usually use manufactured weapons.