The Idiot's Dilemma - a particularly infuriating form of Stupidity Is the Only Option - a puzzle requiring a "correct" solution thwarts the player's progress, in spite of a glaringly obvious alternative solution being available - for example, solving a complex puzzle lock to open a glass door when the player has a hammer in their inventory.It can get especially egregious if it's a common mook that you've defeated by the hundreds, yet the game won't give you the option of trying to shove/push/fight your way past them. to prevent you from going down that path. The Invulnerable Guard - in which a common enemy or hostile NPC is guarding a door, pathway, etc.Particularly annoying if your character is supposed to be at odds with this NPC. The Nagging Voice - in which an NPC stops you from trying to go down another path or otherwise prevents you from deviating from the plot.Some games use an underwater variant where instead an extremely strong current automatically forces the player back when they try to enter a certain passage. The Overpowering Constant Wind - which uses Vent Physics to push you out of an area if you try to enter it.Sometimes justified if there are actually things in the dark trying to kill you or pits to avoid, but more often leaves the player wondering why they couldn't just use one of a hundred different ways to create light. The Impenetrable Darkness - an area which is impassible because your character apparently has a paralyzing fear of the dark.Thus, it's inaccessible because you can't crawl over a tiny obstacle or pull yourself up into a crawl. The Unslideable Passageway - a passageway that needs to be crawled through but isn't at ground level.For whatever reason, your character can't/won't just crouch and move through it. The Impassable Head High Hole - an opening you can't enter because the top of your character's head is an inch too high.The Knee Deep Water of Uncrossability - a body of shallow water which may as well be a Bottomless Pit as far as your ability to ford it is concerned.Especially flagrant when the game doesn't otherwise have falling damage. The Ledge of Instant Death, a type of Gravity Barrier, that looks safe to jump down from, but kills you anyway.The Rough Ground of Unwalkability - an area of rocky or otherwise uneven terrain you can't even step onto.The Endless One Story Staircase - where if you go up (or down) you can climb forever, either because you can't go that way or you missed getting a Plot Coupon that allows you to, and so you could climb those stairs for ten minutes or for three days, but turn around and all you traveled from where you started was maybe a couple meters.The Gentle Slope of Unclimbability - a slightly inclined piece of land which, despite all logic to the contrary, is completely impassable, both up and down.Is essentially the animation version of I Can't Reach It for climbing characters. Often results in the character making a poor attempt at climbing up it when, on the intended path, they'll throw all their energy into it. The Frictionless Ledge - a particularly lazy method of boxing the player in by simply not allowing the character to jump up to and/or grab a ledge that they would normally be able to.The Frictionless Hill - a slope of arbitrary steepness onto which you can jump only to slide off as if the thing were coated in an industrial lubricant.The Impassable Forest - a sparse congregation of vegetation, apparently sporting a force field that expels player characters.The Unclearable Debris - a pile of rubble of some description that is apparently both solid enough that you can't move any of it, yet unstable enough that the game won't let you even consider climbing over it.The Indestructible Fallen Log - A fallen tree which, despite having nuclear weapons and space-warping magic at your fingertips, you can't even chip.