The Parlor Larp mechanics are designed for a single run game of two to four hours. The mechanics have a few intricacies, but at their core are pretty simple.
For each scenario, there are eight characters with a mix of three dualities:
The rules include a single set of diceless mechanics that handle three categories of conflict: Physical (P), Social (S), and Emotional (E). There are no randomizers or guessing (like rock-paper-scissors) for resolution. Instead, everything revolves around Function Levels. Each character has five Function Levels, which are an abstract measure of how well the character is. They combine physical, emotional, and social state. If you are reduced to zero Function Levels, you are out of the game. If it is by physical conflict, you are dead. If by social, you are crushed and unable to function. If by emotional, you suffer a breakdown. Because there are only a handful, you can't engage in many conflicts during a game.
Conflicts are resolved by quick diceless comparison of numbers. In addition, each character has a set of numerically rated conflict abilities, such as "Fighting" or "Intimidate". Each character also has three Resist scores, one for each conflict category.
The basic rule of conflict is simple: the character with the higher score wins. To initiate a conflict, you use an ability marked on your sheet, like Intimidate or Swordplay. You compare your active ability with the opponent's Resist score. Whoever has the lower score loses and takes the difference in Function Levels of damage (unless the ability specifies some other effect). If you go to zero function levels, you are out of the game: dead if by physical, outcast if social, and insane or collapsed if emotional.
The key exception here is that you can sacrifice Function Levels to increase your total in a conflict. Each conflict begins with the two sides simultaneously revealing how many Function Levels they bid. This almost never helps you survive, but may help you oppose other characters or achieve your goals. In short, this is an extremely lethal system which encourages sacrifice to go out with a bang.
There are a few other exceptions, most of which are listed on the character sheets. For example, swords or other weapons will increase the damage done upon a successful physical attack. Also, many conflict abilities only work for a limited range of Function Levels -- so if you are badly injures, you cannot swordfight. Lastly, characters may have special abilities described on their sheets. For example, Hamlet has a special "Soliloquy" ability that allows him to freeze the game to speak. Characters may also have limited use abilities, like "Intuition", which allows the player to ask the Director a yes/no question.