Puzzle Reset

Screw up while doing a puzzle? Did you move the blocks the completely wrong way? Accidentally destroy the crate you needed to reach the high ledge? You're completely screwed, right?

Nope! Simply exit and reenter the room, and more than likely everything will have been restored back to its default position. Convenient, isn't it?

Particularly pragmatic developers will include a Puzzle Reset for puzzles that should be impossible to get stuck in, to avert a possible Game Breaking Bug.

Cousin to Everything Fades and Respawning Enemies. This appears very frequently with Block Puzzles. An Acceptable Break From Reality, because it would not be that fair to make the puzzle unwinnable because the player accidentally blocked completion.

Action Adventure

 * Many games in The Legend of Zelda series.
 * Although it's interesting to note that, in Ocarina of Time, you can't Puzzle Reset the Gerudo Training Grounds if you start using keys on the wrong side of the final room. However, there are enough keys to open every door, it's just that some of them are only available after you get the Silver Gauntlets, which you don't have when the Training Grounds are first accessible.
 * The Legend of Zelda: A Link to The Past had one puzzle that required Puzzle Reset to beat. It was so annoying and non-obvious that the Updated Rerelease replaced it entirely. That said, in the original version you could still skip the puzzle by completing a later dungeon first, giving you access to, essentially, the Cane of Puzzle Skipping.
 * This is the one thing that most fans dislike about Phantom Hourglass, which has a dungeon—the Temple of the Ocean King—that must be revisited over and over. Each time, all previously-solved puzzles have reset themselves and must be redone in order to advance farther down in the dungeon. Did we mention this is a Timed Mission?
 * La-Mulana goes out of its way in the manual to tell you that there are things you can screw up forever. Strangely enough for a game that proclaims its difficulty loudly, most puzzles are resettable (including the complicated Block Puzzles in Hell Temple), and you always have the option of loading a save and trying again.

Action Game

 * God of War takes this one step further, as you needn't even leave the room for the puzzle objects to reappear. For example, at one point early in the game you're tasked with pushing a crate past a group of archers on a higher ledge. If the enemies destroy the crate, a new one automatically appears in the original position mere seconds later.
 * A particularly weird example appeared in the Tomb Raider series—boulder traps would often reset, as if the boulder had spontaneously rolled back uphill, until they were successfully passed. And sometimes then, as well. Occasionally the opposite would happen, usually when it was least convenient.

Adventure Game

 * Myst IV: Revelation is notable for having certain puzzles (such as one involving moving monkeys around trees in order to lure a carnivore, blocking your path, into a trap) which do not reset after leaving. (This is particularly ironic in light of the fact that the above puzzle clearly shows the carnivore leaving the area to follow you—and then returning to exactly the position it was in before you left.)
 * Phenomenally generously for a Sierra game, there's a section in Space Quest 5 where you have to punch holes in certain sections of a card to get it to let the correct lasers through a security lock to open it - and if you get a position wrong, the game explicitly tells you that you've messed it up and gives you the opportunity to reset it, at the cost of a few points. Of course, more traditionally, if you didn't actually pay attention to where said lasers were when you had the opportunity to look at them a while ago, you're stuffed.

Platform Game

 * The sliding-block puzzles in Star Fox Adventures, specifically, the ones where a simple shove sends them sliding like they're on ice, only require that a block hit a wall in order for the puzzle to reset.
 * De Blob has a strange take on it. Your color meter, as well as your color itself, are reset to how they were before you started a mission, yet nothing else is.
 * In Purple, you can find doors whose only function is for reseting a puzzle.

Puzzle Game

 * The DROD series is particularly egregious, as due to its use of monsters as puzzle elements you get both Respawning Enemies and puzzle reset. It even resets some puzzles that have been solved (those these usually have the potential to make the game Unwinnable otherwise). The games usually manage to work in at least one puzzle that relies on this behaviour for its solution.

Roguelike

 * The Sokoban sub-level in Nethack most definitely does not reset under any circumstances. Fortunately, you don't have to finish it; you just get one of two very useful magical items if you do, plus a pile of gold. Additionally, there are several ways to "cheat" if you mess up, though each act of cheating grants you bad luck.

Role Playing Game

 * In the Pokémon games, this can be done while pushing boulders in caves and dungeons. One puzzle in Sylph Co requires a version of this (where mooks are sent back to their original position) to beat.
 * Pokémon XD: Gale of Darkness has one puzzle that can only be solved using the reset - a crate that must be slid into one passageway to unblock another, and the only way to get through the freshly-blocked passageway is to exit and then reenter using the passageway you unblocked.
 * Puzzles in Breath of Fire III would do this.
 * Same goes for Skies of Arcadia.
 * Exception: in Secret of Evermore, if you screw up the jumping puzzle in the pyramid you have to reload and do it again. Unless you saved after screwing it up, in which case your game is now Unwinnable.
 * Vagrant Story would do this with failed and successful puzzles alike, forcing you to redo them just to get back to where you needed to be. On the plus side, it would occasionally time and rate your completion of a room on subsequent visits.
 * The puzzle-rich Lufia 2 Rise of the Sinistrals included a "Reset" spell to reset any puzzle you screwed up, in case leaving and re-entering the room isn't an option.
 * Golden Sun: The Lost Age actually has solving a puzzle depend on the room resetting when you leave. (To move a pillar needed to reach a treasure chest, you need to step on a breakable floor tile. This makes it impossible to actually GET to the treasure chest without falling through the floor and resetting the room. To get the chest you need to exit through an exit near the pillar, go back in, move it, then cross the floor tile that would be already broken if not for this trope.)
 * Another puzzle uses a lever to reset it because you can't leave the room (unless you use magic to leave the entire dungeon).
 * In Wild Arms 1, where puzzle segments are heavily based on Zelda, there was an actual item to reset the room, but it was almost never used. The rooms reset if you leave them anyway. It does save the player the trouble of walking all the way back to the entrance though.
 * Shadow Hearts: Covenant has a variation - the adjustable stairs in the Neam Ruins won't reset unless you leave the dungeon entirely, which can be a hassle if you screw it up so badly that you can't get it back to the neutral position.

Survival Horror

 * The Resident Evil series features this a lot. Except in the case of one sliding block puzzle in 4.