%%Please do not pothole or link to the GuideDangIt page. We know what trope this page is about.
The Pokémon games have more than their fair share of {{Guide Dang It}}s. NOTE: ''VideoGame/PokemonStadium 2'' provided information in-game for Generations I & II that couldn't be found elsewhere in those games, providing an exclusive guide to the games... in a different game.


[[folder: Obtaining Pokémon]]
[[AC: Generation I]]
!!!''Red, Blue'' and ''Yellow''
* Before internet guides were readily accessible, Mew. Of those players who knew there were actually 151 Pokemon, most back then likely didn't even know about the whole "Mythical Pokemon" concept. Mew could also be obtained by GoodBadBugs that weren't discovered for quite some time. The fact that said bugs sounded a lot like the typical absurd [[UrbanLegendOfZelda Urban Legends of Zelda]] did not help matters.
* This is the case for some Pokémon in ''Yellow''.
** The only location to find Psyduck/Golduck is to surf on Route 6 (the route between Saffron and Vermilion), which is a route with one small patch of water that has ''very'' little reason at first glance for the player to feel the need to go about surfing. In addition, the player never comes across a trainer using a Psyduck, and Golduck is only used by one trainer within the end-game's Victory Road. As a result, the player won't have the Pokedex info to know about Psyduck/Golduck's game location until possibly very late in the game.
** For some reason, there's a few catchable Pokemon that will come up as "Not Available" in the Pokedex. The most obvious example of this is Horsea/Seadra where they will come up as being "Not Available", even though it's possible to fish them up with a Rod at some water locations.

[[AC: Generation II]]
!!!''Gold, Silver'' and ''Crystal''
* Many Johto Pokémon fall under this in their debut appearance due to being sidelined for the Kanto ones instead. Overall, they are rarely used by trainers as well as having very low encounter rates and high tendency to flee from battles; compounded by the fact that some of them can only be found by methods not recorded in the Pokédex while some others are simply found in obscure or end-game locations.
** Dunsparce's 1% encounter chance in the Dark Cave is perhaps this generation's most infamous example of this. It doesn't help that there isn't a single trainer who uses a Dunsparce throughout the game. So the player never obtains the information in the Pokedex that Dunsparce is catchable within the Dark Cave.
** Smeargle and Misdreavus are also notable examples as neither one are battled amongst trainers to learn about their hard-to-find game locations. Smeargle is only found at an off the beaten path Ruins of Alph grass area that can only be accessed through Union Cave after obtaining the Surf HM, and Misdreavus can only be found at nighttime on the 2nd Floor of the Kanto end-game's Mt. Silver.
* Some people may not know that it's actually possible to catch Ho-Oh in ''Pokémon Crystal''. That's because in order for the stairwell to appear to enter into the upper floors of the Tin Tower to reach where Ho-Oh resides, you need to have all three of the Legendary Beasts captured. The three Beasts being Suicune, Raikou, and Entei. While Suicune is the easiest to obtain due to it being allowed to be battled straight out on the bottom floor of the Tin Tower, the player needs to hope that they're able to track down Raikou and Entei as roaming encounters all around Johto. The difficult part is that the player won't know where Raikou and Entei are at first since their data isn't uploaded into the Pokédex until the first time the player randomly comes across a roaming encounter. When the player ''does'' finally manage to get hold of Raikou and Entei, it will finally open up the Tin Tower stairwell to ascend up to Ho-Oh. And if that doesn't sound bad enough, you're never told beforehand that catching the three Legendary Beasts will cause Ho-Oh to appear. It just sort of gets told to the player the moment he/she finally has the three Beasts captured.

[[AC: Generation III]]
!!!''Ruby, Sapphire'' and ''Emerald''
* Finding Feebas was difficult in Generation III, if only because the tiles Feebas appeared on were, for some inexplicable reason, tied to what phrase you tell a man in Dewford Town, a location NOWHERE NEAR the route Feebas appears on, and changing the phrase re-randomizes the tiles Feebas is on. There's no given reason for ''why'' Feebas was tied to this catchphrase, and nothing in game to even tell you that Feebas is connected to it at all to begin with. If you want a Milotic, do not listen to the man in Dewford.
* The three legendary golems. Each beast occupies its own inconspicuous cave; these caves are scattered throughout Hoenn. However, to even get into the caves, they need to be unlocked. To unlock them, you need to use Dive in a ''tiny'' patch of deep water on a route at the end of some very fast currents; simply getting to the spot is a result of either trial and error or pure chance. Once you Dive and get into the cavern, you need to be able to read Braille or check the instruction manual. The Braille writing tells you to how to progress - these clues include using Dig ''on a wall'' instead of using it to try to leave the cave like you normally would, as well as putting a Wailord and a Relicanth (two relatively hard-to-get Pokémon that most trainers almost never have in their parties, especially not simultaneously) in specific spots in your party. Then you have to FIND the now-open caves, two of which are in places you can mostly ignore for the entire game. What's even more annoying, each cave has their own little Braille test before you can even get to the Pokémon; one requires you to stand in place, not touching your Game Boy, [[WaitingPuzzle for two minutes]]. Oh, and Emerald changed the method, like placing Wailord last and Relicanth first in the party instead of the other way around.
* Bagon in Generation III, especially in ''Ruby and Sapphire''. It is found in the deepest room in Meteor Falls, an area of the game you most likely forgot about after going through it (unless you're playing Emerald in which case you return there to fight Steven.) Oh, and don't forget to bring a Pokemon with Surf and Waterfall, since they are both needed to progress to the other parts of the area. By the way, this new section of Meteor Falls has trainers in it before you can even reach the room. You can find a Dragon Fang in the small, mostly water-filled room where Bagon is, but other than that, there is no other indications that there is anything special in this room. Bagon has a 25% chance of appearing on the ground section of this area with the added possibility of encountering one beyond Level. 30 (the level in which it evolves to Shelgon), but it is well worth it since Bagon evolves into the pseudo-legendary Salamence.
* So it looks like there's a hole in your Hoenn Dex at No. 151. Turns out it is Chimecho. It can only be encountered in one place, the top of Mt. Pyre, which the player will probably only visit when they need to progress the story. And even when the player is in the area, the grass is out of the way. And even if the player goes to the grass, the chance of encountering a Chimecho is only 1%. So you've got a very rare non-legendary who no one in the game uses or seems to know about hiding in a very out-of-the-way area with no hints that it's there. And it's only good for completion purposes, as its stats are horrendous.

[[AC: Generation IV]]
!!!''Diamond'', ''Pearl'' and ''Platinum''
* See Feebas' entry in Generation III above? Generation IV is much harder in this regard- [[ThatOneSidequest the amount of tiles has been reduced from six to four, Feebas's appearance rate on the tile is lower, and unlike in Hoenn, the tiles change automatically each day.]]
* [[OneHundredAndEight Spiritomb]]. The part about putting the Odd Keystone into the Ruined Tower is intuitive enough, as examining the latter suggests that something could be put in there and hints at what it is, but the other requirement involves interacting with other people in the Underground at least 32 times. There is one trainer on a nearby route who gives you a hint when you talk to him after beating him, though. The person who gives you your first Odd Keystone does give you some hints on what to do with it... Although he's fairly vague, and ''nowhere'' does the game specify exactly how many people you're supposed to talk to while in the Underground.
* Catching a Gible. Pokédex says it's in Wayward Cave, the cave accessed by cutting down some trees by the Bicycle Path and wandering past the grass there? After a couple hours of wandering (and helping Mira out), you'll probably figure out that there's no Gible there. Now go look for an alternate entrance to the cave, one which ''[[BehindTheBlack is blocked from view by the Bicycle Path running above you]]''. You need a Pokémon with Strength and Flash. Then, go to the basement and catch one, while you complete a semi-difficult bike course, at the end of which you also find the Earthquake TM. ''Platinum'' doesn't have the boulder, however, allowing the player to catch Gible much earlier than before.
* After acquiring the Poké Radar in Generations IV and VI, you can find coveted [[PaletteSwap shiny Pokemon]] by using the latter. The actual method, called "chaining", would take at least ten pages or so to explain, so here's the simple version: if you KO or catch a Pokemon in a Radar encounter, the Radar will continue to trigger Pokemon; by traveling to the correct patch of shaking grass [[note]]identifying this is what takes ten pages[[/note]] without any extra encounters, you can find that species again, and the Radar will continue to trigger encounters with the same species of Pokemon this way (making this also a useful trick for Effort Value training, which requires headhunting certain species of Pokemon). None of this is mentioned beyond "sometimes if you use the Poke Radar, differently-colored Pokemon appear". Even then you can still be screwed by the RNG.
* Munchlax, the baby Snorlax, and the only means of getting Snorlax in ''[=DPPt=]'' without trading. It can only be found in [[ScrappyMechanic Honey Trees]], which involves lathering honey on trees, waiting at least 6 hours for a Pokémon to appear (and not more than 24 hours, or the Pokémon will disappear) and then checking the tree, but Munchlax only appear in 4 of the 21 Honey trees. The trees are spread randomly all over the region and you're likely to never come across at least a few. And these four trees aren't the same for everyone - they are randomised and different for each individual save file. And the game gives no indication or hint as to which trees have Munchlax in them, so you're forced to slather all the trees until you find one. Even then, [[LuckBasedMission you're STILL at the mercy of the RNG]], because each of the four special trees has a '''1%''' chance of attracting a Munchlax. SaveScumming won't help; the Pokémon you'll get from a Honey Tree is determined when you slap on the honey, but you can't tell what it will be until 6 hours later. Went to a tree, saved, and found a Combee? Reset all you want. It's still Combee. (Though this is useful for finding female Combee, which are required to get Vespiquen, another Guide Dang It if you didn't know only female Combee evolve. You probably won't discover this by accident, because almost 90% of Combee are male.) And that's not all! If you add more honey to a tree immediately after failing to get Munchlax from it, it has a bonus 90% chance to select another Pokémon from the regular non-Munchlax group, so even if it's a Munchlax tree it now has a 0.1% chance of giving you what you want. You have to harvest another tree before slathering the first one. Not only is this arbitrary and counterintuitive, the game encourages you to screw your chances of success by asking if you want to add honey right after fighting the tree's Pokémon.
** If you have access to Kanto via FR/LG or HG/SS, you can catch a Snorlax there, transfer it to your Sinnoh game, and breed it while the Snorlax holds a Full Incense. Believe it or not, this is the simpler option.
* Dialga and Palkia in ''Platinum''. First, you must find the Adamant and Lustrous Orbs, located in an out-of-the-way cavern in Mt. Coronet that is unlikely to be discovered by most players. Then, you must travel to the Spear Pillar. Players of ''Diamond'' and ''Pearl'' know that there is no post-story reason to return to the Spear Pillar, except to play the Azure Flute which is unobtainable without cheating. Sure, people might want to go to the Spear Pillar just to see if the portal to the Distortion World is still there, but it's not likely that they'd find the orbs first. Cynthia's grandmother does hint that the orbs can summon their respective dragons, at least, but that still doesn't tell you where the orbs are.
!!!''[=HeartGold=]'' and ''[=SoulSilver=]''
* There is a guide dang it with the Johto Safari Zone itself. When the Warden tells you about objects, he doesn't really mention that you simply have to press "A" in the Safari Zone to place the objects. Thankfully, it's a mild example, but easy to miss if you didn't already know.
* A few Pokémon of the third and fourth generations can be found hiding in trees. Now, there are a handful of specimens that are found in very specific trees (and every single tree in the game can be headbutted, so we're talking about thousands of trees). One example: Taillow is found at Cherrygrove, the first city you visit in the game, after a pool of water and over a pile of rocks that can be only climbed after you beat all the 16 Gyms. There are four trees, and you need to headbutt the lower left tree. Even then you can still fight other Pokémon or yield nothing at all even after dozens of tries.
* Tracking down Suicune can be this if you didn't bother with it outside of Mt. Mortar (the one place where you need Cut to enter) ''after'' reaching Vermilion City. In ''Crystal'', the only obligatory Suicune encounter is to the north of Cianwood City before it moves to the Tin/Bell Tower after you obtain Clear Bell following the dissolution of Team Rocket. Here, it is compulsory to encounter it outside of Mt. Mortar so that it will appear just when you leave the Vermilion Harbor, leading to another chase sequence around Kanto before it finally resides on top of the hill at the end of Route 25.

[[AC: Generation V]]
!!!''Black'' and ''White''
* In order to encounter Landorus you need both Tornadus and Thundurus in your party. However, make sure not to forget to bring your own Tornadus/Thundurus, because if the one available on the game you want to catch Landorus on is not yours, then you won't be able to get Landorus. Nowhere is this mentioned, and it can render Landorus [[PermanentlyMissableContent unobtainable]].
* Getting Larvesta, which can only be obtained by either breeding a Volcarona (single one per game, in an area you'll have to visit at least twice for plot, so not as bad) or getting an egg from a trainer at the far end of an otherwise optional, dead-end route. No trainers use it in battle, and it's part of the Regional dex. Fortunately unlike in Gen IV, the National Dex is opened by beating the Champion instead. In sequels at least, Volcarona is treated like stationary legends - if not caught, it respawns upon Hall of Fame.
!!!''Black 2'' and ''White 2''
* You can get Regirock after deciphering an odd but fairly easy puzzle. You may think that you need to solve a puzzle of similar means to find the other two, but no. Registeel is in ''Black 2'' and Regice is in ''White 2''. You need to go to the title screen to your Unova Link settings, manually change the location of the Rock Chamber to either the Ice Chamber or Steel Chamber, and then go capture the mon. Then, you need to trade over the correct key using the Unova Link settings and two DS systems to get the other mon you don't have. MUCH easier than all that malarkey in Gen III, but nothing in the game mentions anything about Unova Link, besides the whole flashback thing.
* Uxie, Mesprit and Azelf. When you enter the Cave of Being after beating the game (which itself is difficult to find, considering one has to surf along an early-game river to reach an off beaten path, much like Sinnoh's Fuego Ironworks), the three Pokemon will fly off so you can catch them. The problem is, you have no idea where they are, and they turn invisible until you reveal them. Bianca will show up at your house to hint at their locations (and even straight up tell you Azelf is on Route 23; surprisingly nice of her if you consider the other examples on this page), and they only reveal themselves after you stand in ONE very specific spot in the entire overworld. They will not be there prior to your arrival like other legendaries. The most frustrating of these to find is Azelf, who appears in a completely random spot on Route 23; at least Uxie and Mesprit appear in front of the Nacrene museum and in front of the stairs on Celestial Tower's roof respectively, so if you try to access either location you'll run into them eventually (although guessing they're waiting invisibly for you to find them there is still a long stretch).
** Bianca (who happens to be visiting your house after triggering the event) clues about where to find the Pokémon are a little roundabout though, such as talking about them being near what they embody (Azelf is Willpower, so near Victory Road, Uxie is Knowledge so Nacrene museum, and Mesprit is Emotion, so the Celestial Tower roof). However, knowing that Bianca tells you these things is a Guide Dang It in itself (or if you happen to speak to her after rematching the Elite Four.)

[[AC: Generation VI]]
!!!''X'' and ''Y''
* ''X'' and ''Y'' have a fair bit of this. The regional Dex is ''massive'', containing a whopping 454 Pokémon. What this means is that nearly every route has at least one rare Pokémon that only shows up there. This is slightly alleviated with the trainers in Battle Chateau who use rare Pokémon so at least you get their dex entries to know where they are located in the game.
* There are also some Pokémon that are only available via the new Horde Encounters. Some of these can reasonably be worked out, as they evolve into other Pokémon you can find on the area, like Bellsprout on Route 14 (or you could just breed their evolution). Others, not as much -- and Arceus help you if it's one of the aforementioned Pokémon that only show up on one route on top of that.
** One noteworthy Horde Encounter is the Seviper and Zangoose variant as it's the only way for the player to catch the version-exclusive Pokémon from the other game. Depending on whether the player has ''X'' or ''Y'', four will appear of the one that's exclusive to the player's current game while the fifth Pokémon will end up being the version-exclusive from the second game. The catch is that given the Seviper vs. Zangoose rivalry in the lore, the four Pokémon will gang up on the one, so it's literally impossible to defeat all four one-by-one in an attempt to save the one Pokémon that's getting ganged up on before it faints. The method to save the one getting ganged up on is to use a multi-target attack that can hit all four of the attackers at once, but even then, said multi-target attack has to still be weak enough to not knock out the Seviper or Zangoose that's being ganged up on.
* Rotom can be found in garbage bins at the Lost Hotel, but only on Tuesdays. Rotom cannot be "seen" in the Kalos Pokédex without catching one (meaning you can't consult the in-game Pokédex as to where they are), and there is no guarantee that any of the garbage bins would contain Rotom. While some of the garbage bins wiggle, hinting that you should check them, the ones that stay still may have Rotom in them too. On all other days of the week, they contain Garbodor.
!!!''Omega Ruby'' and ''Alpha Sapphire''
* There's a locked room in the Sea Mauville that tells you you're being watched when you enter, and reading through some files mentions the Odd Keystone (an item related to Spiritomb). You can encounter a Spiritomb by opening and closing your bag after reading the document about the Old Keystone, but the game never gives a hint about taking that course of action.
* If you thought that the legendary golems were hard enough to find, ''Omega Ruby'' and ''Alpha Sapphire'' bring the trump card with Regigigas. After you get all three Regis, you need to go back to the Island Cave (the cave on Route 105 where you caught Regice) during daytime, nickname the Regice and have it hold an icy item (eg. Castelia Cone or Never-Melt Ice). ''Then'' you can battle Regigigas. Oh, and it they have to be golems you caught ''in that game.'' No fair cheating bringing in transferred or Mystery gift Regis.
* Finding most of the legendary Pokémon originating from the Johto, Sinnoh and Unova games requires fulfilling certain conditions that are never specified. Some require you to Soar around with a specific Pokémon in your party before their Mirage Spot appears. Some of these are logical, like needing both Reshiram and Zekrom to find Kyurem. On the other hand, finding Tornadus or Thundurus requires you to Soar around with a ''Castform'' in your party. Yes, it's related to weather, but it only makes sense in retrospect, and it's unlikely you'll just have it in your party anyways. Some require you to have one or three Pokémon with certain qualities to find- you'll probably find Uxie, Azelf, and Mesprit without even knowing what triggered it (have three Pokémon with maximum Happiness in your party) and Cobalion, Terrakion, and Virizion will likely be the same (have three Pokémon with maximum Effort Values in your party), but finding Reshiram or Zekrom (have a level 100 Pokémon in your party) probably won't happen by accident.

[[AC: Generation VII]]
!!!''Sun'' and ''Moon''
* A new kind of wild battle introduced in ''Sun'' and ''Moon'' are SOS battles. This is where a wild Pokémon may call for an ally to aid it battle against your Pokémon. Usually it'll call another of its kind (either the same form or an evolved relative), but a few Pokémon will call in a different species. Sometimes it'll be a Pokémon that can only be encountered in this fashion. For example, if you want to catch a Sableye, you'll need to get into a battle with a Carbink and wait for it to call in one.
* Of particular mention are 'Weather SOS' encounter tables - in certain regions of the Alolan Islands like the Lush Jungle, for example, the kinds of Pokémon that can be summoned by wild encounters will change when it's raining (or hailing, or sandstorming, or so on). This is the only way to encounter certain pokémon, like Goomy. Out of all of them, one that's the most aggravating to find is Castform. It can be found in all kinds of weather, but it only shows up ''1 percent'' of the time [[note]]unless you caused a different weather effect in an area where it doesn't usually occur, like a Sandstorm in Lush Jungle.[[/note]].
* Getting [[CollectionSidequest all 100 Zygarde Cells and Cores]] to get a Zygarde with Power Construct is [[ThatOneSidequest so convoluted]] that it [[https://www.reddit.com/r/pokemon/comments/5fha3h/an_annoying_little_bug_that_disregards_the/ generated several]] [[https://www.reddit.com/r/pokemon/comments/5f4dpc/spoilers_99100_zygarde_cells_lake_of_the/ reports that]] [[http://www.gamefaqs.com/boards/187276-pokemon-sun/74600542 a glitch]] [[https://www.tapatalk.com/topic/27398-gbatemp-net/450025-last-pok%C3%A9mon-sm-zygarde-cell could render]] [[https://gbatemp.net/threads/pokemon-sun-and-moon-99-zygarde-cell-bug.449765/ the quest]] UnwinnableByMistake; it's hard to tell whether or not this glitch actually exists or if it's the product of a player not realising that he or she didn't pick up an easy Cell elsewhere. Getting the Cores is easy once you know where they are - there are only five of them, and they appear in your house and the homes of the Kahunas - but collecting the 95 Cells is a different story. There's no in-game indication of how many Cells are left on an island or where they are, meaning you have to visit ''every single location '''listed in walkthroughs'''''[[note]]and you can easily overlook areas[[/note]], and some only appear at a certain time of day, meaning you have to scour all four islands and Aether Paradise twice.
* A large number of fishing-exclusive Pokémon in ''Sun and Moon'' (that is, most aside from [[ComMons Magikarp and Wishiwashi]]) have ridiculously low encounter rates... with one exception. Exactly one fishing spot on the entire route will bubble, and fishing while the spot is bubbling will increase your chance of encountering the rare Pokémon. So what is the condition for bubbling? Well, it bubbles by default, but as soon as you successfully fish anything from the spot, the bubbles will disappear and the fishing hole will act identically to any other. You can also move too quickly past the fishing hole to accomplish the same effect. The only way to reset the bubbles is to leave the area and come back (quick for Seafolk village, rather long for Brooklet Hill) or reset the game itself. And on top of that, knowing which rare encounter is present in which route is dependent on finding a trainer who uses the Pokemon in the first place and consulting the Pokédex.
** Mareanie is perhaps the most annoying to catch of the fishing lot since it combines two of the examples mentioned in this section. Not only does the player have to continue fishing in this regard to come across a Corsola, the player then has to hope that it will finally call upon a Mareanie through the SOS mechanic.
* After completing ''Sun'' and ''Moon'', some players may notice that there's an empty slot in the Rotom Pokédex (#165) between Marowak and Magby. That's because this unknown Pokémon happens to be Kangaskhan, who has a rare 1% encounter rate, or has to be called upon by Cubone through the SOS Battle mechanic, at Wela Volcano Park. Players can easily pass over this due to the rarity of getting Kangaskhan to appear, and no trainer is ever battled against who owns a Kangaskhan for the player to learn about its Wela Volcano Park location. The closest hint the game provides is that because Kangaskhan is sandwiched between Marowak and Magby in the Rotom dex, an educated guess can be made that the missing Pokémon will most likely appear along with Cubone and Magby at Wela Volcano Park.

[[folder: Evolving Pokémon]]
[[AC: Eeveelutions]]

* A few Pokémon evolutions in general are guide dang it in the more recent generations since the second one, with what things like certain stat values, time of day, gender or even location affecting Pokémon evolutions. Want a Glaceon? Well, if you have an Eevee, and happen to level it up near an icy rock on Route 217...
** Luckily, you can just press B to cancel an evolution, though even this is AllThereInTheManual... however, this doesn't work if you used an Evolution Stone to evolve it.
** Were you hanging on to Eevee in the hopes of snagging an Espeon or Umbreon for your team, and happened to level up while training in either Eterna Forest or on Route 217? Even ''if'' this just so happened to be the level in which your Eevee reached the point where it would evolve into Espeon/Umbreon, the Mossy/Icy Rock evolutions '''take precedence''' over the happiness evolutions. Hopefully you realized this during the very brief evolution scene and pressed B in time.
** Thanks to HGSS ditching out Mossy and Icy Rocks a few players may not have even realized the developers added them to Unova; then, they unwittingly level up their Eevee in Pinwheel Forest or the basement level of Twist Mountain. On top of that, thanks to the new evolution scene (which removed the silhouette flicker in favor of a vortex effect), it's hard to tell just WHAT it is your Pokémon is evolving into until it's already too late. Fortunately, this sets up a trend for future games to have their own Mossy and Icy rocks as well.
** As though we didn't have enough Eevee-related woes, in Gen VI, it got ''another'' evolution in the form of Sylveon. How do you get one of these? Eevee has to level up with level 2 Affection (from Pokémon-Amie) while knowing a Fairy-type move. This is ''never mentioned in the game'', and it took a while after the game's release for somebody to figure it out. Actually getting your hands on Sylveon is frustrating enough if you didn't know this beforehand, but it's worse if you're trying to get an Espeon or Umbreon instead; if you happened to let your Eevee learn Charm or Baby-Doll eyes, and its Affection is high enough, the Fairy-type move-based evolution takes priority over the normal friendship evolutions. And, unlike Gen V, you have no way of telling what your Pokémon is evolving into until it's evolved.

[[AC: Generation II]]

* Baby Pokémon might count as this: you can only find some Pokémon by breeding their parents. This then requires a [[GenderEqualsBreed female evolution of the baby]]. Which Pokémon are only obtainable therein isn't really explained. To add insult to injury, in the case of any baby introduced from Generation III onwards [[note]]except Riolu[[/note]] this also requires the parent to be holding a certain type of incense. Using a Ditto will also work for breeding when you only have a male.
* Certain Pokémon only evolve if traded while holding a certain item, or if leveled up holding a certain item. These items usually aren't labeled as influencing evolution, and some of them have a beneficial effect, so one might never realize they have a second use.
* Tyrogue will evolve into one of three Pokémon based on whether its Attack and Defense are higher than each other or equal. Strangely, all three evolutions have similar stats and are all offensively-based.

[[AC: Generation III]]

* Milotic in Generations III and IV. If the player is exceptionally lucky on Route 119 (see above), the player can encounter some ugly brown fish called Feebas which the Pokédex urges you to ignore and cannot do anything but Splash around. How does it evolve? Level up with max Beauty stat, one of the stats for Pokémon Contests. In order to raise its Beauty stat, feed it with blue [=PokéBlocks=] (in Generation III) or Poffins (in Generation IV). It's actually harder than it sounds. Generation V has greatly simplified that by making Feebas way easier to encounter, and Feebas now evolves by being traded with the Prism Scale as there's no contest in Unova, which even mimics Milotic's color scheme. O''mega Ruby and Alpha Sapphire'' have brought back the original evolution method, but it's now much easier, since not only has the Pokeblock-making process been heavily simplified, but now your Pokemon are able to eat an unlimited number of Pokeblocks. In addition, it's easier to find Feebas in this game; they have a 5% chance of appearing when you fish in any Route 119 water tile with any rod. What's more, if you fish underneath the bridge on that route at daytime or around a conspicuous large rock in the water near a female Ranger at night, Feebas will always appear.
* Shedinja. Shedinja cannot be found in the wild and despite appearing in the Pokédex after Nincada and Ninjask and obviously being from the same evolution line, doesn't evolve from anything. To get it, the player must raise a Nincada to Level 20 and let it evolve with at least one empty slot in their party and (in Generation IV and later) at least one standard red-and-white Poké Ball with them. Having the Poké Ball is pretty likely already, but most players go around with a full party for the entire game as soon as they are able to do so. Shedinja is also used only by ''four'' Trainers in the '''entire series''': Greta while battling her for Silver Symbol, Bugsy in his rematch team, Inver as one of his possible Pokémon in the Inverse Battle, and an Ace Trainer in Mauville's food court.
* Wurmple evolves into either Silcoon or Cascoon based on a stat that's never alluded to in the game called personality values. While its evolutions can be caught in the wild, they won't know any offensive moves and will never learn any until their final evolution.

[[AC: Generation IV]]

* As of Generation IV, some Pokémon only evolve if they know a specific move when they level up. Some of them make sense - Mime Jr. and Bonsly need to learn Mimic to evolve, and they are known for mimicking things. Yanma and Piloswine need to learn Ancient Power to evolve, and as their evolutions have prehistoric basis, that makes sense. Tangela into Tangrowth with Ancient Power, not so much. Evolving Lickitung into Lickilicky makes no sense whatsoever, as it needs to know ''Rollout'' to evolve, and that has absolutely nothing to do with any of the evolutionary line's abilities. But with Piloswine, it's worse than that; the only way it can learn Ancient Power to begin with is via the Move Relearner.
* Magneton and Nosepass only evolve if leveled up in Mt. Coronet, which apparently exudes a magnetic field that affects the two magnet-based Pokémon. Unfortunately, ''nowhere in the game is it mentioned that Mt. Coronet is magnetic''! An NPC in ''Platinum'' tells the player that certain Pokémon evolve when leveled up at Mt. Coronet, but they never hint as to which Pokémon or that Mt. Coronet is magnetic.
* Then there's Mantyke, which has another unique evolution method... you have to evolve it by ''leveling it up with a Remoraid in your party''. Although the evolutionary line is blatantly associated with Remoraid, it's still a stretch because Slowpoke doesn't require Shellder in the party to evolve and [[{{Irony}} Remoraid hasn't been attached to Mantine since Generation IV]].

[[AC: Generation V]]

* Karrablast and Shelmet. The two have some kind of relation in vaguely-worded Pokédex entries. Evolving them turns out to be more confusing. Not only do you have to trade them to evolve (which is a guide dang it in itself), but you ''specifically have to trade one for the other'' to evolve each. No other Pokémon evolve this way.
* On the other hand, ''Black 2 and White 2'' did its best to avert this to newcomers. You can ask Prof. Juniper via Xtransceiver how any Pokémon in your party can evolve (if possible), and when she doesn't outright tell you every possible way to evolve it (she even explains ''every single method at once'' for Eevee), she at least gives you a clear hint (for example, if you show her either Karrablast or Shelmet, she will tell you they evolve only when traded with a certain Pokémon, leaving you to connect the dots). However, you're still on your own to figure out anything after Generation V, which brings the question of why didn't Game Freak bring a similar feature back in the subsequent games...
* In ''Black 2 and White 2,'' getting Chansey is surprisingly kind of difficult. The player is given an egg that hatches into a Happiny. However, there's no simple way to get the Oval Stone that evolves it since the only ways to get one is to hope that one is randomly looted from a cave dust-cloud encounter, or grind through the entire White Treehollow / Black Tower post-game content until the final item store is unlocked that will allow the player to purchase an Oval Stone.

[[AC: Generation VI]]

* In order to fully evolve Sliggoo into Goodra, you have to reach level 50. Sounds simple, except it has to be ''raining in the overworld'' for it to evolve. The only hints we get are that Route 14 (the first time you encounter Goomy) is raining often and an Advance Tip at Route 17 that indicates one Pokemon evolves in the rain but never states which or it must be raining overworld. There's also the fact that Sliggoo can learn Rain Dance by leveling up, but that still isn't helpful, given that the rain created with this move won't appear in the overworld.
* Inkay to Malamar needs to reach level 30 ''and requires the 3DS to be upside down upon level up''. The only hint is Inkay's preference for reversing.
* To evolve Pancham into Pangoro, it needs to reach level 32 while a Dark-type is in the party with them. While it isn't a big one, it's annoying to those who don't like overlapping types in their party and expected Pancham to naturally evolve without any additions.
* Finding the post-game Mega Stones in ''X and Y'' is more complicated than necessary. First, the player must go to the Battle Maison and defeat a trainer at least once so the rival will appear at Kiloude City. After defeating the rival, the rival will inform the player that Sycamore is at Anistar City. After the player talks to Sycamore, the Mega Ring is upgraded and now the player can find all the remaining Mega Stones. The kicker? The player can only obtain these Mega Stones from 8 PM to 9 PM. Not only that, most of the Mega Stone's location makes no sense. Such as Mawilite is located at an area that most players have little to no reason to go back. ''Omega Ruby'' and ''Alpha Sapphire'' fixes the time issue in that Mega Stones can be found at any time of day before the end of the game, although only a few of them will be available from the beginning - the rest turn up after you calm down Primal Kyogre/Groudon and complete Episode Delta. Even then some of them can be found in counter-intuitive places, just like in ''X and Y''.

[[AC: Generation VII]]

* Many of the new Pokémon evolve using methods detailed in the sections of previous generations. But a completely new requirement is now involves ''Which version of the game you have''. Rockruff evolves at level 25 into Lycanroc, but what kind of Lycanroc you get depends on the version you're playing. You can only get Midday Lycanroc evolving Rockruff in ''Sun'' while doing the same in ''Moon'' will reveal Midnight Lycanroc. Fortunately they can be encountered in the Vast Poni Canyon grass regardless of version. [[spoiler: This kind of restriction also applies to what Legendary Pokémon Cosmog [[MagikarpPower will eventually become]]]].
* A few of the Alolan variants require different methods of evolution from their regular counterparts. For example, both kinds of Rattata evolve at level 20, but Alolan Rattata also need it to be nighttime to evolve.
* Magnetic-based evolutions in this generation. One would think that the power plant at the Blush Mountain would serve as the method to perform this kind of evolution, but it was actually located at the Vast Poni Canyon, which is filled with mostly Rock-types and has no connection to electricity or magnetism at all. What's worse is that Vast Poni Canyon is a late-game area, meaning you have to wait for a long time to evolve your Magneton, Nosepass and Charjabug.
* Evolving Sneasel can be a bit difficult in ''Sun and Moon'', because there's no way to easily obtain the Razor Claw evolution item in the game apart from hoping to get one off of the wild Jangmo-o line in Vast Poni Canyon. And even then, not only do Jangmo-o only have a low 5% encounter rate, it's only a 5% chance that a Jangmo-o, or a SOS Battle Hakamo-o, will actually be holding a Razor Claw. The final Kommo-o stage has a 50% chance of holding a Razor Claw, but the player still has to rely on the SOS Battle mechanic to get it to appear.

[[folder: Game Mechanics]]
* Trying to figure out which Pokemon learn which moves can be frustrating because sometimes there seem to be no rules at all as to what moves a Pokemon can learn at all. Moves learned by leveling up are fairly predictable and tend to be within the Pokemon's own type. As for [=TMs=], Pokemon understandably can learn almost any TM move that is the same elemental type as they are. TM moves outside of a Pokemon's own type is where it really gets confusing. They can be anywhere from reasonable to just impossible. Generation VI does make it easier by selecting Item on any Pokemon in the party, and switching over to the TM tab can show which TM moves are incompatible with that Pokemon.
* Wonder why two or more same of the Pokemon will have different stats at the same level? That has to do with Individual Values. The existence of these stats is only vaguely alluded to in-game outside of a stats judge, and fully understanding the process and its various formulas by oneself without hacking and digging deep into the game files is likely an impossible task. Knowing these stats and understanding them is essential for breeding Pokémon for competitive battling. In fact, this is specifically an Internet Guide Dang It, as even Nintendo's official guides include only very vague information on [=IVs=]. Generation VII eventually makes IV checking more visible to the player.
* Before Generation VI introduced Super Training, thereís Effort Value (officially called Base Stats). After defeating a Pokemon, the Pokemon will add 1 to 3 EV to a particular stat (usually the highest stat of the defeated Pokemon). Gaining a certain amount will raise its stat depending on the Pokemonís level. Pokemon can have a maximum 252 EV per stat and 510 EV in total. However, the system is barely mentioned in the games prior to Generation VI.
* Natures were introduced in Generation III. One might think nature doesnít affect anything at all, but it actually will raise a particular stat by 10% in exchange for lowering another stat. Unless the Pokemon has a Serious, Bashful, Hardy, Docile or Quirky Nature, which doesnít affect stats at all. From ''Heart Gold and Soul Silver'' onwards, thereís a red text for stats that increase and blue text for stats that decrease. But some might think it's the opposite. In Generation VI, the box system does have a search system that not only allows the player to search for a specific Nature of a Pokemon, but also details which stats are increased or decreased by Nature.
* Generation IV introduced Characteristic, which varies for each Pokemon, including the same species. Some might think itís merely FlavorText, but Characteristic actually vaguely indicates one of the stats contain the highest Individual Value.
* The ''entire move list'' in the first generation of games was a guide dang it, because nowhere in the game did any of those moves get their effects described. So you really had no idea what that new move Charmander just learned actually does, you just knew it's a Fire attack with 15 PP. Is it stronger or weaker than that other Fire attack it just forgot? Who knows?
** And still, in Generation II, you don't know if a move is good or not until you actually learn it. Obviously, when you replace a decent move for Swift (60 power, Normal type and ignores accuracy and evasion modifications), this can be frustrating when you deleted a 100% accurate Normal move with 85 or so power.
** There are also several moves that seem a lot less useful than they actually are if you only go by the in-game description. Sacred Fire, for example, is Ho-oh's SignatureMove. Checking its description, "a fire attack that may leave the target with a burn", and it seems to just be Flamethrower with 5 more power and 5 less accuracy. How is that worthy of being the SignatureMove of an [[OlympusMons Olympus Mon]]? Well that's because it has a whopping ''50% chance of inflicting a burn'', while most other Fire moves only have 10%. Only ''Stadium 2'' lists the exact chance. Even worse is [[NinjaLog Substitute]]. None of its in-game descriptions come anywhere ''close'' to describing everything it can do, probably because doing so would require muliple ''pages'' of info. (All only mention it being a "copy that serves as the user's decoy". They fail to mention that it makes you immune to Status moves while it's active, can be passed to others via Baton Pass, and retains the HP used to create it even if transfered to a Pokemon with more or less maximum HP)
* The ins and outs of breeding for movesets is a guide dang it all on its own. Breeding can result in babies that know moves from their parents, which results in expanded move pools for most Pokémon. However, which moves can be inherited aren't told anywhere in the game. Some of them can be inferred (it's easy to figure out that you can breed Thunderbolt onto any Pokémon who can learn it via TM), some of them aren't that surprising (Mud Shot can be learned by an awful lot - but throwing mud around isn't the most mindblowing technique), but some are positively mind-boggling (Aron, a Rock/Steel type that weighs over a hundred pounds and eventually evolves into something weighing nearly 800 pounds, can inherit a move called Aerial Ace, a swordsman-inspired move). On top of that, there's the rule that many guides overlook, in that a baby will inherit a level-up move if both parents know it. Valuable for Pokémon with wildly divergent movelists upon level-up (like Seedot) or anyone looking to breed for TournamentPlay (which sometimes imposes level restrictions, preventing you from acquiring moves via LevelGrinding).
** And while it might occur to some people that if a move can be bred into one species, it could then be bred into another, the extent of chain breeding moves might not be so apparent. Some Pokemon can only learn certain moves if you go through multiple steps to get it. For example, say you're battling a friend who uses a Mamoswine (Ground/Ice), and you try to take advantage of its Water weakness, only to have your Water type one-shotted by a move you didn't know existed: Freeze-Dry (an Ice-type move that has the special bonus of being super-effective against water). You might wonder when Mamoswine learns such a counter-intuitive move. Well it had to be bred from a Delibird. How did Delibird learn it? It was bred from a Lapras. Which in turn was bred from Aurorus, the ONLY breedable Pokemon that can learn the move naturally. And yes this specific chain is the only way the move gets passed on. An extreme example of chain-breeding, but sometimes the move you want takes more work than you'd think to put in, or wouldn't know could even be learned by your mon, so good luck without a guide. Even worse is chain-breeding Wide Guard onto Honedge, who used to require at least ''five different Pokémon, two of which are starters'', and Smeargle can't help here. [[note]]Mantine, Tirtouga, Carracosta, or Alomomola to Mudkip to Turtwig to Paras to Dwebble to Honedge[[/note]]. Thankfully this was changed when Probopass (who can breed with Honedge directly) was given Wide Guard as a level up move.
* There's the Generation IV National Dex. It is unlocked by ''seeing'' (not catching) every Pokémon in the Sinnoh Dex (150 in ''Diamond'' and ''Pearl''--seeing Manaphy, the 151st in the Sinnoh Dex, wasn't necessary--and 210 in ''Platinum''), and to help make this easier, they made it so that every non-legendary Pokémon in the Sinnoh Dex could be seen in a trainer battle at some point during the game. Furthermore, to increase the likelihood that you'd have to beat the game (or come up just short) to do so, the only trainer with a [[MagikarpPower Garchomp]], [[SocializationBonus Spiritomb]], or Milotic (and in ''Platinum'', you can add Togekiss to this list) is the Pokémon League Champion. However, they didn't always make it entirely evident where to find some of these. Examples of Pokémon that could easily be missed:
** Wormadam--in the party of a trainer on a part of Route 214 that you might not even end up visiting at all (in between Veilstone City and Lake Valor, since the first time you visit Lake Valor for plot purposes, you'll be coming from Pastoria City), whose gaze can easily be avoided as she isn't facing the main path.
** Riolu--in the party of a trainer at Ravaged Path. ''Platinum'' remedied this by giving one to another trainer on Route 217, but given the wide-open nature of that route, it's still no sure thing. And the only way to get one for yourself is to go through a sidequest in an optional area while keeping a slot in your party open (which also means no catching Pokémon while you're there) and then hatching an egg.
** Drifloon, which in Diamond and Pearl only appeared in a skippable trainer battle inside Fantina's gym, could be annoying to find as well if you didn't know that one and only one appears in front of the Valley Windworks every Friday. One appears in Amity Square with a Trainer ''and you can talk to it,'' but that doesn't count as viewing it...
** Palkia (''Diamond'')/Dialga (''Pearl'')/Manaphy (''Platinum''): In the original two, the Pokédex data for the legendary not appearing in your game could be obtained by returning to Celestic Town after Spear Pillar and talking to Cynthia's grandmother. In ''Platinum'', both Dialga and Palkia are seen (and uncatchable) on your initial trip to Spear Pillar, but the expansion of the Sinnoh Dex to 210 means that data for the hidden number 151, Manaphy, must be collected. You can find this data in a similar fashion, but a different place: a book in Mr. Backlot's mansion.
** Rotom (''Platinum'' only, as it only appears after beating the Champion in ''Diamond'' and ''Pearl''). Without the guide letting you know you can only catch it in the Old Chateau at night, and that you need a certain key (which can only be obtained during a limited Wi-Fi event) to unlock its various forms...you'd pretty much have no idea it even exists. Later generations made accessing Rotom's forms easier by not making it a one-time event. It is even an easy-to-find NPC trade in Generation V. If you examine the TV during any other time, it at least hints that there's something special about it... However, it ''is'' kind of vague, and if you didn't already know about Rotom then you'd have little reason to examine the TV in the first place.
* Related to above is the ''Diamond and Pearl'''s iteration of the regional pokédex. For some reason, some Pokémon that are introduced in Generation IV are not in them, and which are available and which aren't are mostly random (leading to things like Rotom only available after getting the National dex for example). ''Platinum'' thankfully fixes this problem with the regional dex expansion.
* Before all of this, there was the ''original'' guide dang it of the series: physical versus special moves. You can hammer your way through the game without knowing the difference, but if you want to fight well, it's the very first thing you have to understand. But ''nowhere'' in the first ''three generations'' of Pokémon games are the nine physical and eight special types actually listed -- not even at the trainer schools! It does get listed in Earl's Academy in ''Pokémon Stadium 2'', but it's fair to assume not that many people delved too deeply into what was a pretty minor part of the game, and the help menu in FR/LG while in battle, as described below. Generation IV uncoupled physical/special from move types and added icons to each move showing which of the two it was, so it's no longer an issue.
* The entire Pokémon series is pretty much one giant guide dang it, but one huge one is the whole ElementalRockPaperScissors. The game does explain about super-effective and not very effective hits, and it gives some tips before Gyms, but you don't see a chart anywhere detailing the full list of what resists and what's weak to what. Some can be intuited, like Fire against Grass or Bug, Water against Fire, or Electric against Flying or Water, or Ground against Electric, but quite a lot of them make you scratch your head. Dragon weak to Ice? Rock weak to Ground? Poison weak to Psychic? Dark weak to Bug? Fighting weak to Fairy? You can only find this out through trial and error, which can take a while. Luckily, you can get a type-matcher app in the Generation IV games which helps, and the Generation I remakes had a type-matcher guide if you left the L-Button=Help option on - and the type guide is only available in battle, anyway which adds a new layer of guide dang it.
** Well, nowhere except the original Generation I instruction book, anyway--although it wasn't very clear that "Bad" was supposed to mean "no effect" in that chart. And of course, it didn't cover Steel, Dark and Fairy, or any type-matchups that were changed for Generation II & VI.
** What's more, the type matchups in Generation I were glitched so that while according to the manual, Ghost was supposed to be super-effective against Psychic, it was in fact completely ineffective. Which rendered the already powerful Psychic type a GameBreaker, since it had no weaknesses outside of Bug, a type with few useful Pokémon or moves at the time. Good luck figuring out why your manual was lying to you.
* Transferring your Generation II remake Celebi and/or Beast Trio to get your Zorua/Zoroark. And even if you know to do that, you need to use the Relocator if you want to transfer them before getting the National Dex, and finding it within the maze of buildings that is Castelia City isn't the easiest task.
* Purifying Shadow Lugia in ''Videogame/PokemonXDGaleOfDarkness''. It's said multiple times throughout the games that it cannot be purified, and you're led to believe they're right; using it in battle, giving it Scents, even putting it in the Purify Chamber does absolutely nothing to drop its Heart Gauge. Well, to purify it, you need all 9 sets of the Purify Chamber to be at full tempo, and then you need to put Lugia into any of the sets. This instantly drops the gauge to zero, giving you the ability to purify Lugia. Now, if just putting Lugia into the Chamber regularly doesn't do anything, ''how the hell'' would you know to have ''9 perfect sets'' going at the same time?
** What makes this worse is the fact that the Purification Chamber itself is otherwise fairly intuitive. Having sets at max tempo does help you purify more quickly, so if you've been using the Chamber much it's likely that you already have at least a few sets at max tempo. Still, ''nothing at all'' in the game hints that you need ''all'' sets at max tempo to purify Lugia.
** And then there's the coup de grâce - Lugia's heart gauge will revert back to full darkness if removed from the purify chamber, meaning that you can't finish the process like every other Pokémon. The trick? You need to visit the physical in-game location of the purify chamber.
** However, once you get all the sets to max tempo, the game tells you that Lugia reacts to it, giving you a hint to put it in the chamber. Getting max tempo is still a hassle though.
* The sidequest to trade with the other Gen. III games in [=FireRed=] and [=LeafGreen=]. The first part is pretty straightforward; beat the Grunts, get the Ruby, and catch Moltres early if you want. The second part is nearly impossible to figure out (unless you can read Braille). You're told that the Team Rocket base requires two passwords, and you already have one. You are then expected to go two islands ahead and run all over looking for an ancient ruin, then Cut the door open and fall through holes in the right order. You are given no direction (in your language, at least) at all, then once you find the Sapphire you are robbed and THEN storm the Team Rocket base. Even initiating the sidequest is this if the player visited the first three of the Sevii Islands at the first opportunity (after defeating Blaine) since there is no indication whatsoever that the Team Rocket Grunts at Mt. Ember can be fought, nor anyone telling the player to go back there.
* One very, very small one, and only for those of us for whom Pokémon was one of our first-ever Role-Playing Games. The games start you off in your room in the upstairs part of your house. Going downstairs is intuitive, but ''nowhere does it say that the little floor mat marks the front door of your house''. It's even somewhat {{Lampshaded}} in the help function for the Generation I remakes -- one of the topics you can look up reads something like: "I can't get out of the house! Help!"
* Similar to that last one is the Olivine Lighthouse in ''VideoGame/PokemonGoldAndSilver'' and the remakes. There's one section that involves a blind leap out of one of the lighthouse windows, and without looking it up, it can be frustrating trying to find your way off that floor.
* A more mild example. While one can muddle through by trial and error, Berry growth in Generation IV has driven some tropers to create cheat sheets of Berry growth. As silly as a full-blown spreadsheet sounds, the developers got rather enthusiastic with their Berry system. Each Berry plant has a total growth time between 8 and 96 hours and a moisture rate (between 4 and 35) that is deducted from the soil moisture count each hour. This count is set to 100 at planting and reset to 100 whenever the plant is watered; the final yield of the plant decreases by one berry for every hour the plant spends at zero moisture. Thus, each plant has to be watered with a certain easily calculated frequency to ensure maximum yield. To keep things from being too simple, the dev team added Mulches to either reduce the water requirement while increasing growth time, or decrease growth time in exchange for more frequent watering. With this twist, Berry plants now have three different growth times, and three different minimum watering frequencies.
* Possibly Ditto's role as the [[HotSkittyOnWailordAction universal breeder]]. The only hint is that the only move it knows lets it transform into other Pokémon.
** Also, nowhere in the game hints that non-legendary [[NoBiologicalSex Genderless Pokémon]], which normally can't breed with anything, ''can'' produce eggs when bred with Ditto. Or that the only things that Ditto can't breed with are its own species and the aforementioned legendaries.
*** Although even that analysis isn't quite true. On the one hand, there's Manaphy and its pseudo-baby form[[note]]Unlike every other baby Pokémon, Phione can never evolve into Manaphy[[/note]], the two legendaries that can breed ''at all''. On the other, there's the baby-stage Pokémon, which ([[ChildrenAreInnocent rather]] [[AbsurdlyYouthfulMother thankfully]]) are unable to. Unown, likely due to how unique they are. And, [[AscendedGlitch for some reason]], Nidorina and Nidoqueen, whose flavor text entries [[GameplayAndStorySegregation explicitly mention them taking care of their young]]. Other Pokémon that are also incapable of breeding include Cosplay Pikachu from ''Omega Ruby and Alpha Sapphire'' and Ash's Greninja which is available from the Pokémon ''Sun and Moon'' demo.
* Egg groups, which indicate what Pokémon species can breed with one another. Like elemental types, a Pokémon can have up to two egg groups, but they're quite independent from types: two Pokémon can share a type, yet belong to different egg groups; conversely, two Pokémon can be in the same egg group(s) while having no type in common. Despite its importance in breeding and passing down egg moves, they are not visible to the player and nobody in-game mentions its existence. The full list of egg groups can be found in ''Stadium 2'', but obviously only covers the first two generations. It can usually be inferred that Pokémon of similar body shape can breed with each other (for example, its easy to see that Houndoom and Manectric can breed with each other since they are both based on dogs). However, the game does throw a few curve balls here and there, such as Magmar being in the Human-like egg group despite resembling a dinosaur.
* In [[VideoGame/PokemonGoldAndSilver HeartGold and SoulSilver]], there are the Shiny Leaves. You need to collect five leaves on a single mon and have Ethan/Lyra make a crown out of them in order to add a trainer star to your card. Seems simple enough, but the routes your 'mon can obtain said leaves is dependent on their nature, so expect to comb ''both'' Kanto and Johto's grassy regions and interact with your 'mon to see if a reaction occurs. To make it worse, ''nowhere'' in the game hints to these leaves until you actually find out, at which point Ethan/Lyra give a little info and then leave the rest to you.
* HGSS also have the Gym Leader rematches. You can rematch any Gym Leader in the game, with a souped-up team...if you have their phone numbers. Talking to them in their Gyms won't get you the number. For most of them, you have to find them outside their Gyms, and then they'll give them to you. Most of them have either a tiny window of time in which they're available (Jasmine, Lt. Surge), while others appear well off the beaten path or in places you aren't likely to revisit (Morty, Bugsy). But the absolute worst is Blue. You can scour the world and you'll never find him. To get Blue's number, you have to have his sister massage one of your Pokémon seven times, while said Pokémon is at maximum happiness, then she will give you Blue's number.
* Finding the Seven Sages in ''Black & White'', most of them are in places where you fought [[AnimalWrongsGroup Team Plasma]] in main game but two of them are in out of the way areas that have nothing to do with Team Plasma.
* ''Black 2 & White 2'': The Dropped Item sidequest. You may even miss picking up the key item on your way through the game, not even knowing it was there. The item in question is a Xtransceiver that belongs to a person named Yancy (if you chose the male Trainer) or Curtis (if you chose the female Trainer). You have to scour the main hexagon of Unova, for ''15 specific areas, and on a specific tile'' to trigger a call from them. After that (getting called ten times by Yancy/Curtis), comes the second part of the quest. You have to call them in the above mentioned 15 areas (not on the same tile, just being in the route/town counts this time). Where you can call them is randomized, meaning you have to run/fly around Unova to the designated areas, and their number will disappear after every call (and you need to either wait a day or go to a different area)...and it takes a total of '''50''' phone calls to get your ultimate reward: unlimited daily trades in which Yancy/Curtis will trade a Lv. 50 'mon (with its Hidden/Dream World ability) for ''any'' 'mon. Good luck trying to figure all of this out without the aid of an online guide.
* There are 5 Berries which restore 1/8 of HP, but confuse Pokémon who hate its taste. This is not as much as problem in Generation III and IV, where the tag options exist (bag description of HGSS outright states the taste), but Generation V? They say "If held by a Pokémon, it restores the userís HP in a pinch, but will cause confusion if it hates the taste.", but ''nowhere'' in the game it is stated which berry has which taste or even what taste ''is'', so unless you've played older games or feel like experimenting... Of course, they're inferior to Sitrus Berries, which restore 1/4 of max HP but with no chance of confusion and they take effect if the Pokémon's HP reaches below half, not below quarter. But the game never tells you ''that'' either. [[BalanceBuff Seemingly to make up for this]], ''VideoGame/PokemonSunAndMoon'' buffed the healing to 1/2.
* There are certain Abilities that have overworld effects if you put the Pokémon with it as your lead. However, most are never alluded to:[[note]]Note that all listed below work only Emerald onwards. There's also Pickup, Honey Gather (which may give items), Illuminate and Stench (doubles and halves encounter rate, respectively); these work in all games[[/note]]
** Arena Trap: Encounter rate is doubled.
** Compound Eyes: Wild Pokémon that can have held items are more likely to have them.
** Cute Charm: Pokémon is 66.7% of the time opposite gender of leading Pokémon, regardless of ratios. Doesn't work on swarming species and in Hidden Grottos, though.
** Flame Body and Magma Armor: Eggs hatch twice as fast, doesn't stack.
** Hustle, Pressure and Vital Spirit: Makes higher-levelled Pokémon more likely to be encountered.
** Hyper Cutter: In Emerald only, doubles radius of Cut when used in tall grass.[[note]]This use of Cut was removed in Generation IV[[/note]]
** Intimidate and Keen Eye: 50% chance that a Pokémon won't appear if it's at least 5 levels lower than the lead.
** Lightning Rod: In Emerald only, increases the chance that NPC Trainers will call you.
** No Guard: Encounter rate is increased by 50%.
** Quick Feet and White Smoke: Encounter rate is halved.
** Sand Veil and Snow Cloak: Encounter rate is halved if player is in an area with sandstorm or hailstorm, respectively.
** Static: 50% of the time game will force an Electric-type encounter, if possible.
*** Similarly, but less obtusely, Magnet Pull's ability to attract Steel-types is never actually explained, but it's pretty obvious when you think about it. It can also cause Magnemite problems in Ruby, Sapphire, and Emerald if you enter New Mauville with a Nosepass, or give you lots of Klink and Ferroseed encounters if you enter Chargestone Cave with a Magnemite.
** Sticky Hold and Suction Cups: More likely to find a Pokémon while fishing.
** Swarm: Increased encounter rate.
** Synchronize: Some Pokémon you meet have a 50% chance of having the same Nature as that of lead Pokemon.[[note]]Affects wild Pokémon that are not roaming. In Emerald only, does not affect stationary Pokémon like Rayquaza. Since Omega Ruby and Alpha Sapphire, it also affects gift Pokémon that cannot breed, like Latios. Does not work in Pokéwalker or Entree Forest.[[/note]]
* The SOS battle mechanics are further affected by Abilities in Generation VII in ways that are not directly explained or made clear:
** Intimidate and Unnerve increases the rate that Pokémon will call for help. For those familiar with the usual application for Intimidate in the overworld, they might think that it will do the opposite and decrease the calling rate instead.
** Rather than the ''lead'' Pokémon (the one that inititates the start of the encounter) possessing the ability you are using to manipulate encounters, in SOS battles it is the ''active'' lead Pokémon (who is in battle right when the SOS calls are made) that will affect the encounters being generated with abilities like Synchronize, Compoundeyes, Cute Charm, Magnet Pull, and Static.
* Join Avenue in [=B2W2=]: Recommending shops to people walking down the avenue can be tricky. Some requests can be as vague as "I want to go there!" or "Where do you think I want to go?" The player would have to look up exactly where in order to avoid them leaving out of disappointment. The only one that's safe is "Please take me to a shop you recommend" where any shop is allowed, which is '''not''' the case for the similarly phrased "Take me somewhere! Anywhere!".
* The Boutique located in Lumiose City won't allow you in until you are stylish enough. [[YouKeepUsingThatWord They don't mean that you have to look pretty, rather, you need to get a hidden stat to a certain level before they'll let you in]]. There are a number of ways to increase this stat around Lumiose, but nothing actually tells you that these things make you more stylish and the dialogue when you get kicked out of the boutique seems to suggest that you basically just need to visit every building in town.
** On a similar note, a number of other services are unlocked or have their prices reduced as your style rating goes up. That old guy in the stone shop selling Mega Stones for 500,000 Pokédollars? Get your style rating up high enough and it drops to ''10,000''. The Art Mueseum? ''Gives you the Audio Guide to the gallery's pieces for free'' rather than require a token small payment of 200 Pokédollars. The Hairdresser? For girls, she'll eventually treat you as a regular customer ([[LesYay and get ...distracted... by how enchanting you look]]), which unlocks a few more options of hair customization.
** The final O-Power, the highly useful Hatching Power, is difficult to find, let alone get. To get it, you need to max out your style and go to Café Introversion, where Mr. Bonding will be if you did everything right. Knowing that you have to max out style, and even where to find the last O-Power, is not hinted at anywhere.
* What about Trainers and their Pokémon's movepools, during Trainer Battles? In Gen I and Gen II, the majority of their movepools are level-up moves, which means that at the very least, you've got a pretty good idea what type their Pokémon's moves are most likely to be. Only Gym Leaders would use TM moves. Fast forward to Gen VI, and now it seems like they'll source their Pokémon's moves from anything, including [=TMs=] and Egg Moves. [[TheComputerIsACheatingBastard (Sometimes even from cheating.)]] And there's absolutely no telling what abilities their Pokémon will have too without consulting a guide, creating another avenue to screw up your strategies. And this is not just for Gym Leaders, but regular trainers too.
** And this is just the main series. The Orre games are happy to give out TM and Egg moves to random mooks.
* Trying to figure out which Pokemon learn which moves can be frustrating because sometimes there seem to be no rules as to what moves a Pokemon can learn at all. Moves learned by leveling up are fairly predictable and tend to be within the Pokemon's own type. As for [=TMs=], Pokemon understandably can learn almost any TM move that is the same elemental type as they are. TM moves outside of a Pokemon's own typing is where it really gets confusing. They can be anywhere from reasonable to unreasonable and sometimes just impossible. Generation VI makes stuff easier by selecting either "Restore" or "Use Item" on a Pokemon and switch to the TM tabs, all the incompatible TM moves for that Pokemon will be grayed out.
* Invisible items have been scattered around the overworld since Gen I. Some of them are on conspicuously odd bits of terrain, but others are in completely random places, and there's no way to know anything is there unless you stand facing that exact square and press A, or use the Itemfinder. Getting the Itemfinder is often a Guide Dang It in and of itself. (In gen 1 you have to talk a specific assistant of Oak--not in his lab, but in a gate between routes on the other side of Kanto--after catching at least 30 mons. Oak will mention this only if you happen to talk to him when you've caught between 30 and 39 mons--any other amount triggers a different message--and he doesn't tell you where the assistant is.)
** Speaking of the Itemfinder, in its original incarnation in Generations I and II, it only indicated the presence of a hidden item, but did not drop hints as to where it was. Happy easter egg hunt! Thankfully later incarnations of the Item Finder/Dowser make it more user-friendly by letting it indicate which direction the hidden item was. Even so, there is still yet ''another'' undocumented Item Finder behaviour in [=FireRed=] and [=LeafGreen=] - At certain special locations (Where Mr Fuji, the two Snorlax, Giovanni (in Viridian Gym) used to stand before leaving their location, as well as tiny patch of land by the Cape Brink's pond [[spoiler:and Navel Rock]]), standing exactly where these folks used to be and using the Itemfinder will produce a unique reaction that reveals a special item ([[spoiler:Mr Fuji's spot in Lavender Tower has a Soothe Bell, there are Leftovers where the two Snorlax used to be, Giovanni was standing over a Macho Brace the whole time, that tiny patch of land by the pond has PP Max, and if you had access to it, you could find Sacred Ash on Navel Rock, in addition to the one Ho-Oh holds in Emerald.]]).
** ''Omega Ruby'' and ''Alpha Sapphire'' takes this to a whole new level in the underwater areas. The original games at least had "invisible" items be marked by a noticeable bulge on the seabed, but in the remakes the items are completely invisible. You are unable to use the Dowsing Machine while underwater, which means that you are forced to trawl every inch of the seabed in case you miss an item which may or may not even be there in the first place! Some of these are easy to find, since they're in otherwise completely empty areas, or in rather conspicuous gaps in the middle of the seaweed, but how is anyone supposed to know that there's a Pixie Plate in the middle of ''nowhere''?! There's even a necessary PixelHunt for the Scanner in the submerged part of Sea Mauville, as giving it to Captain Stern nets you the Clear/Tidal Bells, which is needed to open up Ho-oh/Lugia's portal on Sea Mauville. And depending on your version, either one of them are needed to be in your party while soaring to find the Legendary Beasts.
* Before ''[=FireRed=]'' and ''[=LeafGreen=]'', Stick and Thick Bone had description of [[VendorTrash vendor items]], while in reality they increase Farfetch'd's critical hit ratio and Cubone and Marowak's Attack, respectively. They were one of the few items to get description changed in Emerald, where it was corrected.
* In ''Omega Ruby'' and ''Alpha Sapphire'', it's possible to obtain both types of bicycle at once. Not only does this save a lot of time, it means you can fully traverse the Safari Zone, and a few of the mirage islands, which requires both bikes. How do you do this? Just talk to three completely random people who are all off the beaten path (one of them is found in the Battle Resort, which you can't access until after the Delta Episode) and then go talk to Rydel. ''Nowhere'' is any of this mentioned. Even the fact that you can obtain both bikes at all is never brought up even by Rydel himself! Your only hints is that there are areas that blatantly ''need'' both bikes to get to, and the people you need to talk to disappear when they comment on your bike, but that still does nothing for figuring out how to do it.
* Starting in Gen III, you can get stars to appear on your trainer card based on your performance in the game. Beating the Elite Four and Champion, seeing and catching all regional Pokémon, completing the National Dex, etc., all seem fairly logical. However, even ''then'' some of them don't make sense, such as the Shiny Leaves mentioned above. Every time you get a star, your card changes color as well. Starting in Gen V, the stars don't show up anymore but the card still changes color, with no indication of what rank each color is other than when you first start. You could easily rank the card up twice in a row without realizing it and never see one of the colors, or have it maxed out but not know it without outside help. They also changed it from 5 ranks in Gen III to 6 in Gen IV, then down to 4 in Gen VI. Thankfully, the changes are purely cosmetic and it doesn't affect the game itself apart from getting special dialogue from nurses in Pokemon Centers.
* Getting to the Pokémon Village in ''X and Y''. You need to head west into a roughly t-shaped part of the forest, [[AlienGeometries go back the way you came which now leads somewhere completely different]], then turn around again to enter a part of the forest that looks similar (but not identical to) the first t-shaped area. Now you are free to head west to the Pokémon Village.
* Although a good chunk of [=TMs=] are this, the worst of them all is Energy Ball in Generation VI. In ''X and Y'', it's found in Route 20. Said Route has paths that usually lead to areas the player wouldn't expect and you need Cut in order to get that TM. In ''Omega Ruby'' and ''Alpha Sapphire'', you require ''both'' bikes, which is already a huge Guide Dang It in itself, and it's found in the Safari Zone, also well off the beaten path. It doesn't exactly help Energy Ball is actually a very useful move, either.
* The Mirage Islands of ''Omega Ruby and Alpha Sapphire''. They open up once you've gotten the Eon Flute after calming Groudon or Kyogre. However, which island(s) you can access is random and they change daily. More of them can be accessed at a time when you streetpass other players, but usually you'll only have access to one of them at a time. Many of these islands also house rare species of Pokémon that cannot be obtained anywhere else in the Gen VI games (not even in the Friend Safari Zones of ''X and Y''). Many islands also have rare items, including [=TMs=]. One of the islands even has a Cresselia, but unlike other islands that have legendaries, this one also appears and disappears at random. Also in order to fully explore some of the islands, you need both bikes.
* From Generation VI onward, Destiny Knot has an additional effect when a Pokemon hold it and put it in a Day Care, five of the parents Individual Values will be passed down to its child. However, no NPC gives any hint about Destiny Knot's additional effect at all.
* Breeding a non-Alolan Pokemon in Generation VII. Requiring a Pokemon in their regular form sounds simple enough. However, the Pokemon must also hold an Everstone in order to work, otherwise, its baby will be in its Alolan Form.
* Entering Saffron City in the Generation I games and their remakes. The first time the player attempts to enter (from Cerulean City) the only path into the city will be blocked by the security guard, and the player has to go around, and every other guard on every other path to the city says the same thing. The only hint as to how to get in is that the guards mention that they are thirsty before telling the player to wait because the road is closed. Much later in the game, the player can buy drinks, but only at a single vending machine which only exists on the roof of the Celadon Department Store, which a player could easily overlook. Even when the player gets them, nothing in the game says that they can now enter Saffron, and so the player might well avoid the city until they can do nothing else. This means that a first-timer could wind up fighting Blaine (the seventh Gym Leader) before Sabrina (the sixth). It's even worse in the remakes, because instead of getting a drink from the vending machines, the player must instead get a Key Item from an old woman in the Celadon Mansion, when there was nothing important on the ground floor of the Mansion in the originals. This is especially true since this is the ''only'' thing changed in the main story.

[[folder:Mystery Dungeon]]
[[VideoGame/PokemonMysteryDungeon Mystery Dungeon]] is a dungeon crawler rather than an RPG. This means the series has its own share of moments.

[[AC: Multiple games]]
* First off, finding out which dungeons spawn what items. Some dungeons even add or remove items as you progress through floors.
* Rescue Team and Explorers assign you to be a certain Pokémon depending on your answers in the quiz. Each question awards hidden points that are used to calculate your result, on top of being dependent on the chosen gender. [[labelnote:Note]]While few Pokémon are outright gender-exclusive, most simply change the Nature result you need for it.[[/labelnote]] Even if you know this beforehand, there's no guarantee that you will get as set of questions that'll allow you to choose the Pokemon you want. This problem is fixed in Super where you can just pick a Pokémon yourself if you don't agree with the choice.
[[AC: Rescue Team]]
* All evolutionary items are found only in certain dungeons, either as a random or a scripted item. The worst offenders are Link Cables, which appear in place of the scripted items you've already got, and the few evolutionary items that you can get only if Wish Cave generated a shop on one of the ''12 specific''[[labelnote:Which ones?]]13, 26, 33, 41, 49, 59, 65, 71, 78, 83, 88 and 93. Have fun.[[/labelnote]] floors. [[ShaggyDogStory With only the last two guaranteeing that the shop will have an evolution item.]]
* To recruit Pokémon, you need Friend Areas. However, the game never tells you that certain legendaries' FA are given to you ''by'' recruiting their residents.[[labelnote:Which ones?]]Legendary birds, Lugia, Celebi, weather trio and Deoxys[[/labelnote]]
* The best way to find buried items is to dig a long corridor in seemingly unused portion of the map (if you walk in the naturally generated corridors, you might sometimes see that map left a big chunk without any rooms or corridors). and then run back that corridor. This is because if you suddenly stop in a corridor for no apparent reason, it means there's a buried item near you.
* Unlike other legendaries, Mew is simply spawned (with a really low spawn rate) like other dungeon Pokémon, meaning if you fail to recruit it, you can try your luck at later floors. Even the guidebook's not really helpful on this.