The Calling uses the Accelerant System (formerly the nTeract System) developed by Robert Ciccolini. The system ensures safe combat while maintaining an in-game atmosphere. This excerpt is taken from the Madrigal website:

The Accelerant live action system (formerly known as the nTeraction system) is designed to allow a rich set of skills and abilities without an overly complicated rules set. The system is designed to allow a great deal of options in creating and advancing characters, and allows for hidden and secret skills without needing extra rules to deal with those abilities.

With the Accelerant system, we have taken every opportunity to allow the player's actions to speak for themselves. Most of the active skills require real interaction from the player. The rules handle the resolution of our staged combat, allow rogues to actually work game locks and disarm game traps, allow mages to throw battle magic and summon spirits, and even encourage musical performance with a set of Troubadour skills. Our staged combat stresses role-playing, and we use boffer weapons and packets to represent weapons and magical effects.

The Accelerant system is designed to allow the game to flow without holds or stops in the game play. Every facet of the game, from the rules to the plot to the staff characters, is designed to create a tale without interrupting play. We will work hard to stay in game, and we ask that our players do the same.

The Calling Rulebook 1.2 (pdf format)

The Calling Character Generator

Quick View Guides (pdf format)
o Skills
o Spells

As with every site, there are some rules that everyone must follow while at Camp Spindrift.

o The pool is off-limits. No exceptions. (Unless we have a life guard on duty and only when authorized by the staff)
o Leave the camp in better condition than you found it.
o Have respect for those who live in the neighborhood around the camp.
o Only smoke in the area designated by the staff.