Invisible Block

""I gotta just get right over there, wait for the firestick, aaaand up WHAT?! WHO PUT THAT THERE?! Where did that come from?""

""Okay, so just gotta get on that little jumpy platform, the little AAH YOU FUCK WHY DID THEY DO THAT?""

""WHO DID THAT""

- Super Mario Brothers - Frustration

""9, 8, 7, 6, 5, 4, f*** you Yoshi- *hits invisible block* AHHHHHHHHHHHHHHHH WHAT?!?!?""

- Proton Jon, Kaizo Mario World, Special Stage 2

In platformers, there are blocks. Blocks to walk on, blocks to jump on, blocks to hit from below for some reward. Not all of these are apparent, however; some are invisible.

These are primarily meant to be used as secret rewards hidden in the environment. Other times, these are the method of moving past obstacles. In Platform Hell, they're very often a quick way to death; your Double Jump leads to blunt head trauma and a fall into the Spikes of Doom.

Sometimes interacting with the blocks will make them visible, but some may remain invisible. Sometimes, the blocks aren't even physically there until they become visible through some specific method.

Action Adventure

 * The Legend of Zelda a Link To The Past featured late-game dungeons with crystalline blocks that could only be revealed by bright light --either by igniting strategically placed torches, or by using a medallion that summoned lightning-like magic. Once the lights went out, the blocks would vanish again.
 * Ocarina of Time had several invisible platforms that became visible when you viewed them with the lens of truth.
 * Majoras Mask featured invisible blocks at one point in the game--there was a random cave floating out a hundred feet or so from the edge of an icy cliff. The only way you could see these blocks was by talking to "the owl," who flew over and shed feathers in the process, which would land conveniently in the middle of each block.
 * The first mansion, Berkeley Mansion, in Castlevania 2: Simon's Quest is famous for having the invisible platforms that turn visible when you obtain and equip the White Crystal in the opening town of Veros.
 * The mansions are also packed full of the Invisible Block's cousin, the Fake Platform.
 * Invisible platforms in An Untitled Story are visible only when you stand on them, or for a short while after you flip the screens around.

Adventure Game

 * In the Lost City in Hype: The Time Quest you need to get to an otherwise inaccessible door by jumping on invisible blocks. However, when the camera angle is right, the stained-glass windows shine on them, making them appear VERY translucent red.
 * There are glitches and hacks in Minecraft that let you place two separate types of these. Invisible blocks work just like any other block, but you can't see them, playing the trope straight. Intangible blocks, on the other hand, only interact with other blocks while the player passes through them just like air. The second block type is very useful for making elevators and other special redstone machines the player must pass through.

First Person Shooter

 * In Metroid Prime, one room in Tallon Overworld has invisible platforms, seen with the X-Ray Visor. Or by looking closely at the environment and noticing the ambient rain splashing on their surface. The Magmoor Caverns had some with no clue to their presence, aside from a huge otherwise-unused part of the room.
 * Star Trek Elite Force has an area with a Bottomless Pit and a bridge made of invisible forcefield "panels". The panels appear briefly when shot, meaning that one essentially has to walk around with their phaser (the game's Infinite Ammo weapon) blasting the whole way.

Platform Game

 * Tomb Raider III featured invisible blocks that became visible if you had a flare lighted near them or some other fire source was present. A secret in the penultimate level required this knowledge in order to be accessible.
 * The first Tomb Raider had only one invisible block in the Sanctuary of the Scion level - the level's only secret with the Uzis as a prize. All you had to do was notice the unusual sight of a pair of guns hanging in mid-air.
 * The remake Anniversary did away with the platform and instead had the guns on the Sphinx's head. Getting down was a bit more tricky in this version.
 * And to complete the trilogy, Tomb Raider II featured a rather well-hidden secret: the entrance is hidden behind a perfectly unassuming section of wall that turns out to be a movable block, opening into a huge room with an invisible walkway to the other side.
 * Super Mario Bros. has these in abundance, and is probably the Trope Maker. However, unless the player hits an invisible block's location, it doesn't "exist" (can't jump on a block, or forward momentum remains while against a block's side). The more sadistic Platform Hell ROM hacks of the games often have them in places you don't want them to appear - to add insult to injury, the item coming out of the block is often a 1-UP.
 * Hidden item blocks also show up in Paper Mario. They can be revealed with Watt's field ability, though it's not strictly necessary if you already know where to jump.
 * Kaizo Mario World basically started this trope off in Platform Hell games. And a hack called Furious Mario has to be the literal most annoying user of this as in this video.
 * Enigmatic Mario Seriously. What the hell?!
 * Proton Jon, known for playing Super Mario World romhacks, got so fed up with people using invisible coin blocks that he made an entire level filled with them, in order to show what not to do when making a Mario romhack.
 * They come in two flavors in Super Paper Mario - one type is revealed by flipping to 3-D, while another type requires using Tippi to scan the screen.
 * Portrayed rather accurately in this Brawl in The Family strip.
 * Special mention goes to Super Mario Bros.: The Lost Levels. Its use of this trope brings it closer to Platform Hell romhacks than pretty much any other commercially-released game.
 * I Wanna Be the Guy has some of these. Of course because of the nature of the game they show up in groups and constitute major paths rather than giving bonuses.
 * In Within a Deep Forest, one part of the sub-level Shadowlands has invisible platforms that only become visible while the player is very close to them, so there's a good chance you'll hit one from below and bounce back down where you came from. Making this part more aggravating are the visible platforms that are not solid in the least.
 * In Mega Man 7, Cloud Man's stage has a section where the floor is invisible outside of a very limited radius around Mega Man. Additionally, this part of the stage is usually raining, making seeing the translucent platforms even harder.
 * In Commander Keen, the blocks are at least vaguely visible if you pay attention. In the first game, they have one visible pixel which shows up against a black background, and in the fourth game, they sparkle briefly every few seconds.
 * The ones in episode one also never appear anywhere except against a black background, thanks to the block and background actually being the same tile.
 * Syobon Action, as in other Mario-based Platform Hell games, has plenty of them in the most uncomfortable locations. The game knows this and later, especially in the sequel, does some mean tricks if you try to reveal them from safe ground.
 * Secret Agent has an interesting example: You can't see the invisible platforms, or even stand on them, until you find some magic glasses.
 * In The Life Ending Adventure, a Japanese ASCII Platform Hell game that inspired I Wanna Be The Guy, there is at one point a Mario Shout Out level that uses these sadistically.
 * Crystal Caves uses these infrequently; they appear, and actually become solid and physical, when you bump your head into their bottom. They mostly appear in the later games. There's a level where you first need to spend some 10 minutes building up a very sparse staircase of invisible blocks to get up to the higher parts of the level (jump off the highest current block, hit the next invisible block which is to the side and just barely within jump reach, fall to the bottom of the level and re-climb all the blocks). Not cool.
 * Bug! had Burrubs Scene 3. An area with blocks that only appeared when Bug was near. The first set was easy, as there were no enemies. The second set had a hell of an annoying snow flea throwing snowballs at Bug from the background, as well as acid-spitting flies that came from nowhere.
 * A similar case appears in Bug Too! At least there were enemies that crossed the platforms, so that you could see where it ended... but there were also random comets that traveled across a horizontal section of said platforms. Not fun.

Puzzle Game

 * In the puzzle game Chip's Challenge, certain blocks are invisible and may or may not appear when touched. Since most levels are timed missions, this can get aggravating when entire mazes are built of them.

Role Playing Game

 * The Final Dungeon in Shin Megami Tensei Nocturne had these.
 * The fortress of Organization XIII in Kingdom Hearts II presents an enormous abyss with random floating platforms scattered throughout. Only by running (or gliding) towards them could Sora reveal the prismatic pathways linking the platforms (and the exits) together. Possibly a subversion, as Edge Gravity remained in full effect, making the...invisibleness...just there for show.