Upsidedowned

Gravity pulls you at the sky.

The world is exactly the world you know. You are the thing that is wrong with it. Your screen is upside down, and if you stop holding on you fall — up, past the treeline, past the clouds, until the sky kills you.

For Minecraft 26.2 (Fabric).

Installing

1. Install Fabric Loader for Minecraft 26.2.
2. Put upsidedowned-1.0.0.jar and Fabric API in your mods folder:
   • Windows: %appdata%\.minecraft\mods
   • macOS: ~/Library/Application Support/minecraft/mods
   • Linux: ~/.minecraft/mods

Everyone should install it, including the server. The physics work without it on the client — gravity is sent as an ordinary attribute, so a vanilla player will still fall upwards — but the picture is drawn by your own machine. Without the mod on your client your screen stays the right way up while you sail into the sky, which is disorientating in entirely the wrong way.

Works on an existing world. The terrain is never touched.

What it does to you

Gravity is reversed. You accelerate towards the sky at exactly the rate you used to fall at. There is no floor any more; there is a ceiling, and it is the only thing between you and the void above.

Your screen turns over. The whole view rolls a half turn, so the world is upside down in front of you.

You are not upside down. The world is. Your model is drawn the right way up, and every control does what it looks like it should do -- walk left and you go left on screen, drag the mouse right and the crosshair goes right. You are playing ordinary Minecraft; it is the world that has turned over.

Making that true takes three corrections, because a half-turn of the view mirrors the screen both ways and moves where your head is:

• Strafing is mirrored back. Walking left carries you towards the left of the picture. Forwards is untouched, because the roll is about the direction you are facing.
• The mouse is mirrored back, on both axes, so the crosshair follows your hand.
• Your eye is measured from the other end of you. This is the big one. Gravity presses you against a ceiling, so the surface you are standing on is the top of your hitbox -- but eye height is measured from the bottom, which left your viewpoint two tenths of a block off the floor you appear to be standing on. Your head felt like it was at your feet because it was. It is now a normal eye height below the surface you are standing on, and the camera, your reach, fluid checks and mob line-of-sight all agree about it.

Ceilings are floors. You walk along the underside of things, with normal friction and normal step-up. Jumping pushes you away from the ceiling — down, into the open air — which is now the most dangerous button on your keyboard.

Falling still hurts, upwards. Fall damage is measured on the way up instead of the way down. A long drop into the sky will hurt when a canopy finally catches you, exactly as much as the same drop to the ground would have.

The sky will kill you

There is no bedrock up there and nothing to land on. Get more than 24 blocks above the top of the world and it starts doing to you what the void does from the other end: four damage a second, until you are gone. Your items go with you.

That is the whole tension of the mod. Everything you do happens under something.

Where you spawn

Under a tree.

When you join, the mod looks for a canopy with open air underneath it and puts you in that gap. A tree is the first ceiling most of the overworld has to offer, and its underside is exactly the pocket that catches you when you start rising.

If there is genuinely no tree within range — a desert, an ocean, a spawn that has been stripped bare — it plants one and puts you under that. You are never dropped into open sky.

The same check runs when you respawn without a bed, and /upsidedowned shelter runs it whenever you want it.

Playing it

• Trees are shelter. Forests are the safe biome. Plains are a death trap.
• Caves are the safest place in the world and, for once, going down is going somewhere safer.
• Look up before you jump. Or rather, look at whatever is above your head, because jumping now sends you the other way.
• Water still holds you. Swimming works; you just float towards the surface from underneath.
• Blocks are a ceiling you can build. A single block placed overhead is a handhold. Roofing becomes the first thing you do anywhere new.
• Boats, minecarts and horses are unaffected — they still fall down. Riding one is a way to travel across open ground you could not otherwise cross.
• Mobs are unaffected too. They walk around the right way up, on the ground, while you hang above them.

Commands

Turning it off puts gravity back the right way round and un-flips every screen, live.

Settings

A file appears at config/upsidedowned.json the first time you run the mod.

gravityStrength: 0.4 is the friendly version of this mod. You drift up slowly enough to grab at things, and the whole game stops being a reflex test.

Things worth knowing

• Vanilla clients can join. They fall upwards like everyone else and die in the sky like everyone else; they simply see it the right way up, and their controls are not mirrored, so it is playable but strange.
• Elytra work, and are the best item in the game here, because falling upwards is just falling and an elytra does not care which way.
• Turning the mod off mid-flight drops you. If someone is a hundred blocks up when you run /upsidedowned off, gravity reverses and they come straight back down.