The Lost Room

What this mod adds

The Lost Room introduces a single, carefully crafted mystery into your Minecraft world: Room 10, a motel room that exists outside of normal space. A unique key — the Room 10 Key — can open a portal to it through any door in the Overworld.

The Key

There is exactly one Room 10 Key per world. It can be found in:

Stronghold library or Woodland Mansion chests (1% chance by default, configurable)
A Wandering Trader (20% chance per trader, costs 50 Emeralds + 20 Eyes of Ender — only offered if the key doesn't already exist elsewhere in the world)

The Portal

Right-click any door with the Key to open a portal to Room 10 in front of it. The Overworld door never physically opens — it becomes a window.

Only one portal can be active at a time. Using the Key on a second door while another portal is open does nothing.
Shift+right-click to physically place the Key on the door (visible as a HUD icon when nearby).
The portal stays open as long as the mirror door inside Room 10 is open, or the Key is on the Overworld door.

Inside Room 10

Room 10 is a fixed, hand-crafted motel room loaded in its own dimension. All Object powers are disabled inside.

Objects never disappear from the room. When the room resets, every Object found anywhere inside — in inventories, on the floor, in containers — is recovered and repositioned at its canonical spawn location. Nothing is permanently lost.

The reset: If the portal closes while the Key is still inside the room, every player in the room is killed (inventories lost) and the room resets to its initial state — completely reconstructed.

The exit — and the real power of Room 10: If you're inside with the Key and the portal has closed, you are not truly trapped. Interacting with the mirror door opens a destination selector: choose a specific door you've previously interacted with, a random Overworld door, or enter approximate coordinates. This makes Room 10 a fast-travel hub to virtually anywhere in the world

Objects

Scattered across the world — in loot chests, on the ground, or in Room 10 itself — are 36 unique Objects. Each is a recognizable item given a hidden power.

Rules that apply to every Object:

Only one copy per world. The mod enforces this continuously.
Indestructible outside Room 10 (fire, explosions, lava, void — nothing destroys them as items).
Powers only work outside of Room 10.
The power of each Object is hidden until it activates for the first time. The tooltip is blank until then.

Objects are either items (held or in inventory) or block-objects (placeable blocks that gain a passive effect when placed in the world or held in inventory depending on them).

Two Objects are always present in Room 10 at world creation. The remaining 34 can spawn in any natural loot chest worldwide (1% chance per chest, configurable), weighted by rarity.

Object list (spoilers)

Items — passive (in inventory) or active (on use)

Object	Power
Pen	Hitting an entity sets it on fire and knocks it back
Coin	Right-click to enter coin-flip mode — lets you rewind to a saved state if you win the game
Comb	Freeze time for 10 seconds
Pencil	Hitting a block releases a a small amount of XP orbs
Scissors	Right-click to rotate entities or blocks at up to 20 blocks range. Opens/closes doors at range. In offhand: +15 block reach
Alarm Clock	Right-click a block to smelt everything in a 3×3 area around it after a 5-second countdown
Right Shoe	Hitting a block "uncraft" it
Phone	Right-click to teleport the item in your offhand to the last chest you opened
Razor	In offhand while sneaking: hostile mobs within 10 blocks target each other instead of you
Toilet Paper	Right-click to lay a path of white wool 20 blocks forward, which disappears after 15 seconds
Bus Ticket	Hit an entity to make it vanish and teleport to the Motel structure in overworld. Crouch+right-click twice to teleport yourself
Iron Helmet	Potions you drink take effect at the next tier (amplifier +1)
Gold Chestplate	Eggs you throw explode on impact
Iron Leggings	Punch a sheep with bare hands to randomise its wool colour
Diamond Boots	Eating food drops a gold or iron nugget
Shield	Anyone who hits you while you hold it is launched 10 blocks into the air
Potato	Right-click to teleport 500,000–500,000 blocks away in a random direction. You return automatically after 1 minute. 15-minute cooldown after return
Wheat Seeds	Silently duplicates a random item from your inventory every 10 minutes (40% chance each cycle)
Flint & Steel	Right-click during a fall to redirect your momentum toward your look direction (5-second cooldown)
Stick	Fire heals you instead of dealing damage. Effect ends temporarily when you reach full health (10-minute cooldown)
Ender Pearl	While in your inventory, prevents rain in the Overworld
Spyglass	Passive creatures within 5 blocks of you are immune to all damage

Block-Objects — place them in the world to activate

Object	Power
Lectern	Placing it causes a knockback burst in an 8-block radius. With a Book & Quill placed in it, materialises mobs or ore blocks written in the book
Jukebox	Cancels creeper explosions within 16 blocks
Anvil	Never degrades (chipped/damaged → restored automatically). Gives you frost walking and lava walking while in your inventory
Enchanting Table	Prevents death if you have 5+ XP levels — instead restores 2 hearts and halves your XP
Armor Stand	Accelerates crop growth within 10 blocks
Chest	Repairs items stored inside by 1 durability point every 5 seconds
Barrel	Opening it randomly transforms a nearby block into a different vanilla block (60-second cooldown)
Bed	Lying in it for 15 seconds teleports you 100 blocks upward with a temporary Elytra
Furnace	While smelting, grants Speed III and Jump Boost II to all players within 10 blocks
Stripped Oak Log	The block directly above it receives 5× faster random ticks
Crafting Table	Crafting anything at it produces a random potion effect (70% positive, 30% negative)
Obsidian	All items and armour in your inventory lose durability at half the normal rate
Glass	Crouching on it for 5 seconds forces your camera to snap toward the nearest diamond ore within 32 blocks
Spruce Trapdoor	Placing it on ground will create a vertical space shortcut to the ground
Book & Quill (item)	After 5 minutes in your inventory, permanently suppresses hunger

Planned features

Object combinations: specific pairs of Objects carried together will alter or amplify their individual powers
Lectern + Book & Quill fix: stabilise materialisation edge cases for complex written entries

Configuration

All major values are exposed in the Forge config (thelostroom-server.toml): key and Object spawn rates, Wandering Trader probabilities, door search radius, Pen power multiplier, and more.

Inspired by the TV series The Lost Room (2006).