Core Mechanic
Roll 1d20 + Rank/Modifiers vs. Difficulty Class
Equal or exceed the DC = success. Every trait — ability, skill, power, defense — has a rank, from −5 to 20+, which is also the modifier added to its checks.
Critical Success: a natural 20 scores a critical success — figure the degree of success normally, then bump it up one more degree.
Routine Check: outside pressure, just use a flat result of 10 instead of rolling.