The Interlock System is R. Talsorian Games' proprietary role-playing system.
History
Interlock was a game system by R. Talsorian Games based on a simple ‘die + bonus’ system, using a d10. Mekton II (1987) – the 3rd edition of R. Talsorian's mecha game – revealed for the first time the full-fledged Interlock system. Interlock featured point-based characters with a character background system that had appeared in Mekton, though in a more complex and comprehensive form called Lifepaths. Cyberpunk 2013 (1988) was R. Talsorian's second Interlock design. Cyberpunk expanded the original Interlock system by introducing a new combat system called "Friday Night Firefight". The second edition of the game, Cyberpunk 2020 (1990), polished up the Interlock system once more, producing what is now known as "Standard Interlock".
Interlock is one of the direct parents of the Fuzion system (the other is the Hero System). The Interlock System is "skill-based"—characters are created by choosing skills for them, and by advancing those skills individually, rather than by choosing character class packages. The Interlock System is used primarily in the Cyberpunk 2020 and Mekton role-playing games; a variant of the Interlock System is used in Teenagers from Outer Space and the Japanese Gundam Senki RPG. Stats and skills are both rated on a scale of 0-10 with 0 representing no ability/no training and 10 representing the maximum ability possible for a human being. A typical skill roll will range from 12-20 for most tasks, so a skill 10 + stat 10 will succeed at virtually any task barring a critical mishap, while a skill 0 + stat 2 (minimum statistic level for a human character) will fail at any but the very simplest task, and even then will succeed only on a critical success. Interlock builds on the typical skill-based paradigm by offering "template" (Mekton) or "profession" (Cyberpunk) packages that give specialized abilities to characters that take these packages.
The Interlock System is best known for its Lifepath system, a storytelling device used to create character backgrounds without particular direct benefit or drawback to the character, avoiding min-maxing.