Betrayal at House on the Hill

Betrayal at House on the Hill (and yes, that's the actual title) is a unique Board Game published in 2004 by Avalon Hill. Three to six players take the roles of various character archetypes, such as a Jock, a Final Girl, a Professor, a Fortune Teller, a seemingly sweet little girl or a curious young boy... Each miniature has two different 'characters' attached to it, such as the Scientist doubling as a Preacher Man. Whatever their role, the cast find themselves trapped inside a haunted mansion and set out to explore, with players drawing and setting out floor tiles with each new room they enter.

However, sooner or later, somebody's going to trigger the Haunt, revealing the Mansion's terrible secret—and one of the heroes turns on the rest. A wide variety of scenarios are included with the game—players can end up facing Giant Spiders, Vampires, Werewolves and other monsters, or find themselves playing Chess with Death, suddenly shrinking, or dealing with the house flooding or collasping into a Black Hole. And since the house is built anew during the exploration phase, every game is a different adventure.

Sadly, the design is a bit clunky in areas. While plastic minis were included to represent the heroes, monsters are represented by paper punch-out counters (probably because of the sheer amount of creatures that can be involved). Upon the Haunt occurring, Heroes and Traitors must split up to quickly read over their booklets on the scenario, which can cause the game to stall out a bit. Worse yet, the game was originally published with a few errors, leading to even more game-stopping confusion and frustration. Betrayal can prove quite fun with the Errata and the various fan-created content floating around. The second edition fixed most of the problems as well as adding a number of new haunts.

Betrayal at House on the Hill can contain examples of

 * Alien Geometries - One of the easier ways to explain the Mystic Elevator. Especially if there are secret stairs connecting to it.
 * Ambiguous Innocence - That teddy-bear toting girl might turn out to be in league with the minions of hell.
 * Badass Preacher - In the right scenario, Father Rhinehart is distilled badass.
 * Brainwashed and Crazy
 * Cats Are Mean -
 * Actually, this troper ended up
 * Chess with Death
 * Closed Circle
 * Damsel in Distress - Some Haunts involve NPC victims that require protection.
 * Face Heel Turn
 * Five-Man Band, arguably. There's The Big Guy, The Smart Guy (well, if you use the preacher he becomes The Sane Guy instead), and The Chick anyway.
 * For the Evulz
 * From Nobody to Nightmare - The Traitor tends to become this once the Haunt hits.
 * Game Mod - Lots of fan-created content can be found floating around; one notable example are Splats and cards for the Scooby Doo gang.
 * Giant Spider - And plenty of other nasty oversized beasties.
 * Go Mad From the Revelation - More than one Scenario starts with this happening to the Traitor.
 * Go Through Me - Since movement is slowed by hostile characters, and creatures can only attack once per turn, it is possible for a well coordinated team to buy a character a round or two to make a vital roll.
 * I'm a Humanitarian - "The Feast."
 * Incredible Shrinking Man
 * It Got Worse - The house is full of creepy omens, hauntings, and ominous rooms. It's even possible to become crippled and teeter on the edge of sanity just by initial exploration, depending on your luck. Then the Betrayal starts...
 * Malevolent Architecture
 * Man-Eating Plant
 * The Mole - half of the scenarios.
 * Monster Wants To Marry
 * More Than Mind Control
 * Mummy
 * Not Himself
 * Obvious Beta
 * Oh Crap - A frequent utterance when the Haunt is revealed and you realize the random map has completely hosed you.
 * Our Ghosts Are Different
 * Rapid Aging - One of the scenarios. The two children are often the sole survivors.
 * Sanity Has Advantages - Literally. Rolls on the Sanity stat are often crucial to winning, or to staying alive.
 * Stat Death - If any of a character's stats fall below the skull at the bottom of your sliding counter, they'll find themselves dead if the haunt has been revealed.
 * Unfinished Business
 * Unwinnable - If the traitor turns out to be the guy who's got all the weapons? Or they have to collect Mac Guffins and already happen to have them? Yeah, um...
 * Add in that before the Errata, some Scenarios had conflicting rules or goals that made winning impossible.
 * Also, because the map is mostly random, save for what floor a given tile can be on, and that some scenarios require the heroes to be in a certain room/rooms, it is possible that the traitor and his/her army of demons/plants/etc. could be revealed and/or spawn in such a way that they perfectly block the path the heroes need to take to win. This can be especially bad when combined with the first example.
 * Vampires
 * Werewolves
 * Wicked Witch
 * Zombie Apocalypse