Master Hardcore Mode is a Gamemode-in-a-box that changes the rules for how Minecraft is played.

Just add it to a world's spawn chunk (I'll post a world soon from my Let's Play).

The three new rules are:

1. It's always night after the first bit of day (you have an option to play a full day).
   
2. Animals don't give you food (so farming is important).
   
3. You can't craft chests (though Ender chests and naturally spawned chests are ok to use).
   

The box enforces all these rules for you and also turns Ultra Hardcore on by default (you have an option on the back to turn that off too).

Requires the newer 1.8 snapshots (for the updated clear command).

Enjoy!