Chests will show up on any ground surface with air, water, or snow above it. By default, there's about a 10% chance of one in each chunk of terrain (either above or below ground). I've tried to add these reliably, but due to issues with the game itself, about half never show up in the world. So, I doubled the spawn rate. An ABM would be more reliable, but that's not how I want them to work.
Chests also have a chance of poisoning you (if my status mod is in use), turning into a lit TNT block (if tnt is in use), or dropping you into a deep pit. I'm working on having them spawn monsters in some fashion.
NOTE: This mod requires my status mod to poison anyone. It can be downloaded here: https://github.com/duane-r/status/archive/master.zip
Screenshots
Recipes
The source is available on github.
Code: LGPL2
Mod dependencies: default
Download: https://github.com/duane-r/booty/archive/master.zip