Dead Tree Games currently works with three different TRPG game engines. Each game engine is designed for a different gaming experience.
The Hit ‘n’ Miss System™ is a lightweight system that uses pools of d6s to resolve conflict. It is a story-focused system that is intended to be simple enough for young kids to understand, but rich enough for adults to enjoy. This engine powers both Playthings and Mischief.
The PITCH System™ is a robust system that uses coin pitches to resolve conflict. It is a more complex system designed to reflect real-world situations and simulate real-world physics. This system powers Chronoplex.
The Knock Out System™ is a fast-paced system that uses pools of d12s to resolve conflict. It is a quick and dirty system designed for a pulpier, fly-by-the-seat-of-your-pants game experience. No setting has employed this system yet, but check back for updates.