Reflex

Check
You may check whether or not your reflex can Dodge the action unit's basic attack or Projectile ability when responding to an attack. Before damage calculation, you may choose to Block, Dodge, Oppose, or perform a defensive ability. The DC of the check equals the speed of the action unit. The responding unit must meet or surpass the DC with the check (d10 + Ref).

Defense Check
In order to successfully pull off a defensive ability you must perform a Defense check. The DC of the check equals the speed of the action unit. The responding unit must meet or surpass the DC with the check (d20 + Ref).