Betrayal at House on the Hill
Betrayal at House on the Hill is a board game published by Avalon Hill in 2004, designed by Bruce Glassco and developed by Rob Daviau, Bill McQuillan, Mike Selinker, and Teeuwynn Woodruff. Players all begin as allies exploring a haunted house filled with dangers, traps, items, and omens. As players journey to new parts of the mansion, room tiles are chosen at random and placed on the game board; this means that the game is different each session. Eventually the "haunt" begins, with the nature and plot of this session's ghost story revealed; one player usually "betrays" the others and takes the side of the ghosts, monsters, or other enemies, while the remaining players collaborate to defeat them. Wikipedia