Big Brother

Every mob knows where you are. Always.

No walls in the way. No sneaking, no hiding, no waiting for the sun. If the server is simulating it, it is already hunting you.

For Minecraft 26.2 (Fabric).

Installing

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

Only the server needs it. Vanilla clients can connect and play normally, right up until they are killed.

Works on an existing world.

What changes

Normally a mob has to notice you: you have to be inside its detection range, in its line of sight, and not sneaking or invisible. Every one of those checks is gone.

Hostile mobs see you from anywhere the server is simulating -- your simulation distance -- and the result is that they target you. A mob outside that is frozen and hunting nobody, so reaching further would buy no extra menace at all.

Seeing and chasing are two different numbers, and that is what keeps this playable. Sight costs a distance comparison. Chasing is limited separately, because a mob's follow range is what the pathfinder sizes its search from -- it copies every chunk in a cube of that radius before it even starts looking for a route. At vanilla's 35 that is about thirty-six chunks. At a simulation distance it is over four hundred, per mob, several times a second, which is exactly what made an earlier version of this mod freeze servers. A mob that can see you but is too far to path to simply walks at you instead, which needs no pathfinder at all.

Walls do not help. Standing behind stone, underwater, in a sealed box, under a trapdoor — it knows.

Sneaking does not help. Neither does an invisibility potion or a mob head.

Darkness does not help. There was never a light check to begin with; the difference is that there is nothing else left either.

Every hostile mob is re-pointed at the nearest player once a second, which also means killing a mob's aggro is impossible — it comes straight back.

This includes mobs that use the newer brain system and normally ignore ordinary targeting: piglins, hoglins, ravagers and the warden are all pulled in as well.

What it does not change

• Passive mobs are left out. Only hostile mobs hunt. The same targeting checks the game uses to pick a victim also answer "can this cow see the wheat you are holding" and "should this creeper flee from that ocelot", so this mod only answers the combat ones -- a cow following you across the world was never the intention and no longer happens.
• Creative and spectator players are invisible to it, so an admin can move around.
• Mobs still have to reach you. They path towards you like any mob would; they simply always know which way that is. A mob on the far side of an ocean will walk into the water and start swimming, and get there eventually.
• Nothing spawns any faster. The mobs that hunt you are the mobs that were going to be there.

Commands

Settings

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

Turning seeThroughBlocks off keeps the range but restores line of sight, which is a noticeably more survivable game.

Things worth knowing

• Build a roof first. A sealed base still works — mobs cannot walk through walls, they can only see through them. They will queue up outside it.
• If the server stutters, lower chaseRangeBlocks, not visionBlocks. Sight is nearly free; chasing is the expensive half, and it is the one that scales quadratically.
• This pairs viciously with Mobility, which lets mobs dig through the walls they can now see you behind. Running both is a very short game.
• Raising retargetIntervalTicks to 40 or 60 makes it slightly cheaper and gives you a moment of respite after killing something. Lowering it to 5 removes even that.