From the Game's Introduction:
Fungeon is roleplaying the ancient art of dungeon crawling, only without a gamemaster. During play, each Player creates Traps, Monsters and Treasure for your adventurous Fungeoneers to escape, fight and discover.
To play Fungeon, you will need tons of dice, all of which must have the same number of sides. Each Player needs one die which is distinguishable from her others, most likely one of a different color. This is called the Thwack-O Die and is discussed in the Narration section.
Fungeon also requires you to do a lot of scribbling, so everyone needs tons of scratch paper. If you are going to map out your adventures, graph paper is recommended.