Dungeon Crawl: Stone Soup

An open source roguelike adventure through dungeons filled with dangerous monsters in a quest to find the mystifyingly fabulous Orb of Zot. Crawl may seem easier than many other roguelikes at first glance, but dig a little deeper and you'll find it's just as challenging as some of the most difficult variations out there and a good deal harder than the rest. A strong set of design philosophies makes it much friendlier (and generally fairer) to the player - deaths are a learning experience instead of an exercise in frustration. Crawl also sports a number of systems and mechanics that diverge from more traditional roguelikes. For example, there's less emphasis on character classes (or backgrounds in Crawl parlance); your character is defined more by their skills, species and choice of deity than their background. Crawl includes an in-game tutorial and manual in the name of providing something playable without the aid of a guide or wiki.