This adds a new dungeon to the game. Why would you want it? The walls drop or can be smelted into slimeballs, the mob in there drops slimeballs and the chests can contain slimeballs.
- Download and install Minecraft Forge.
- Download Slime Dungeons Mod zip file
- Put Slime Dungeons Mod zip file into your /.minecraft/mods folder. Do not unzip it.