* The ''Zelda'' series typically has the boss of each dungeon's weakness based around whatever piece equipment Link finds in (and sometimes before) it. For example, if you find the Bow expect to be shooting arrows at a weak spot, if you find a hammer then expect to smash some armour and so on. The more recent a game is, the more they do this.
** Early on in ''VideoGame/TheLegendOfZeldaOcarinaOfTime'', Link can learn how to use Din's Fire, a reasonably useful area-effect fire spell, but like the other magic spells, not perfectly necessary. It isn't until he gets to the Shadow Temple that Din's Fire becomes ''essential'', as its the only way to light the torches at once and open the doorway.
*** And to get rid of the [[DescendingCeiling big walls of wooden spikes]] that are protecting the [[InterchangeableAntimatterKeys Boss Key]] for that temple.
** We also have Bombchus, which were featured very early on in the game as a minigame in Hyrule Castle Town that you could win prizes from. However, they become a necessity in both the Spirit Temple and Ganon's Castle later on.
** In ''[[VideoGame/TheLegendOfZeldaOracleGames Oracle Of Seasons]]'', the Rod of Seasons can be used to smack enemies out of the way, but it doesn't actually do any damage, which makes it useless...right up until phase 2 of the final boss.
** And odd little one shows up in in ''VideoGame/TheLegendOfZeldaTwilightPrincess''. Near the beginning of the game, if you speak to the mayor of the village, a goat comes flying out of the Ordon ranch, and you either catch it by holding 'A' or get run over. This 'skill' is used in the final fight with Ganondorf, while you're both in animal form.
*** The goat-catching skill comes into play a lot earlier, when Link is climbing DeathMountain and ends up dealing with charging Gorons in the same manner, officially making this a ChekhovsBoomerang.
** In ''VideoGame/TheLegendOfZeldaSpiritTracks'', you can go through the whole game without ever using the Spin Attack. But while protecting Zelda from Maladus, you'll have to do it THREE TIMES with almost PERFECT timing.
* In ''VideoGame/TalesOfEternia'', Rid gets the Kyokku skills (Aurora Artes) in three parts. The first two form his two-stage "Hi-Ougi", the high-powered low-HP sort of move most Tales leads get at some point. The last one is completely useless (and unusable) except as a requirement for the final PuzzleBoss.
* Inverted in ''JadeEmpire'', where many characters comment on a mysterious seemingly unexploitable "flaw" in the protagonist's martial arts, one or two theorising that his teacher included it to trap opponents. Once the nature of the flaw is revealed it turns the plot completely upside-down.
* In ''TraumaCenter: New Blood'', Valerie drags the operating team to a demonstration held by her friend. Unfortunately, she doesn't realize that her friend became a veterinarian. Any attempts to salvage the situation as having learned something useful are shot down by Markus as being highly unlikely, since human doctors would never have to operate on a dog. Much later in the game, a dog that had been given to them is shot, and they decide to use the skills they learned earlier to operate on it.
* Parodied in ''VideoGame/FinalFantasyIX'' - early in the game, Vivi, being too naive to understand how to escape a captor, is easily kidnapped from the party. With Garnet standing right next to him, Zidane explains how to successfully resist capture. Later in the game, when Garnet is about to be captured, she only remembers to yell "Let go of me, you scumbag!", to the perplexity of the villains who then proceed to grab her anyway.
** The trope is inverted in Disc 3. Kuja's final plan is to use the power of Trance, the game's LimitBreak mechanic.
* Inverted in ''VideoGame/FinalFantasyVIII'' - Ultimecia's trump card is summoning Griever, and finally, Junctioning with it.
* Serah is mentioned to have been working as a ground school teacher at the beginning of ''VideoGame/{{Final Fantasy XIII-2}}''--and ruling her classes with an iron fist. Much later (''literally'' 400 years later), her IronLady skills finally come to use when she chases away a horde of juvenile semi-sentient monsters by yelling at them as she did at her misbehaving students.
* ChekhovsGun are the order of the day in any [[PointAndClickGame Point and Click]] [[AdventureGame Adventure]], since most objects you can pick up will undoubtedly become useful later. The ''VideoGame/MonkeyIsland'' series also includes the occasional skill.
** Insult Swordfighting, which is required to progress through several points in the game.
** A neater example comes at the end of ''VideoGame/MonkeyIsland2LeChucksRevenge'': [[spoiler: at the beginning of the game, you were taught how to make a voodoo doll to defeat Largo [=LaGrande=]. At the end of the game, you must recall this skill to defeat [=LeChuck=].]]
** The most amusing example comes from ''VideoGame/TheSecretOfMonkeyIsland'', in which Guybrush mentions that one of his qualifications for becoming a pirate is to be able to hold his breath for ten minutes. Later in the game, someone attempts to drown him...and the player has exactly ten real world minutes to get him out of the water. This is also the only way Guybrush can actually die during the game.
* In VideoGame/DevilMayCry 4, Nero, not Dante, is the main character of this one. One key feature of his gameplay is his claw, the Devil Bringer. You kill the final boss exclusively with it.
* In ''VideoGame/MechAssault 2'', a key gameplay gimmick was the power armor that could latch onto the body of a mech, hack into it and force the pilot to eject so you could jack it. The last boss is a new, ancient mech that is crawling on it's hands because it's incomplete. You have no mech and the situation looks bleak. The only way to kill it is, yes! Latch onto it and hack it to it reveals a weakpoint.
* Shinobi for Ps2: Your sword, Akujiki, will kill you unless you satisfy it's hunger for souls. At the end of the game, the homosexual-looking wizard reveals his true goals all along. Turn everyone in Japan into demons, set you loose against them, and steal the cursed sword once it's full. Oh, wait. You can use the Tate system you've been using the whole time to kill him instantly.
* In ''VideoGame/EarthBound'', Paula's 'Pray' ability seems somewhat useless and unnecessary at first. You have to use it to kill the final boss.
* ''VideoGame/{{Fallout 1}}'' included an optional perk called "Mental Block". This perk would allow you to resist [[BigBad the Master's]] psychic attacks, with the game describing it as "the ability to tune out any outside mental interference. You must have learned this talent from a passing guru, or from a really late night at a bar."
* At the start of ''VideoGame/WildARMs4'', Jude Maverick is scolded for missing his sword-fighting lessons. Completely averted when he is then given a ''[[{{BFG}} gun]]'' to use for the rest of the game.
* In ''VideoGame/{{Banjo-Kazooie}}'', one of the many basic moves learned at the beginning of the game is a crouch attack which propels you forwards. However, with the huge amount of other moves at your disposal, especially the other crouching moves, it can be easily forgotten fairly quickly. So, when you're trying to get a MacGuffin by destroying multiple outer layers that can only be broken with a specific move in a specific marked spot, you might just end up scratching your head at what move you need to do for that really low spot...
* At roughly the midpoint of the main quest in ''VideoGame/TheElderScrollsVSkyrim'', you learn the [[MakeMeWannaShout Thu'um]] Clear Skies, which you use to reach [[spoiler:Paarthurnax]] by clearing away the freezing mist on the Throat of the World. [[spoiler:This Shout gets used again in Sovngarde, to clear the MysteriousMist Alduin has shrouded the place with and provoke him to battle.]]
* Done in ''VideoGame/SuperMarioWorld'', funnily enough. The one skill you ''will'' need to defeat the final boss (punting an item up in the air) is taught to you in ''the very first level''.
** Also in YoshisIsland; to defeat Naval Piranha you need to be good at bouncing eggs off the wall [[spoiler: -- well, or hit it before Kamek transforms it --]] so it's lucky that ''entire boss level'' drills it into your muscle memory. You know, just a spot of tutorial.
* In ''MegaManZXAdvent'', Model A may be your default form, but you have many better choices for combat. By the time you reach the final boss, you'll have nearly forgotten you have it... much less that it has a homing shot which is practically ''designed'' for taking out the boss's multipart shield.
* At one point in ''VideoGame/GoldenSun'', Master Hama speculates that Proxian antagonists Saturos and Menardi were able to pass through the Lamakan Desert without Reveal -the spell that the heroes use to pass through the desert, and the Proxians do not possess- because their [[PlayingWithFire Fire Clan Psynergy]] shields them from extreme temperatures. In the sequel, Agatio and Karst, who are also members of the Fire Clan, freeze to death in Mars Lighthouse because the BalefulPolymorph and subsequent battle with the heroes they had been subjected to left them too weak to maintain this ability.