Rogue Trader 2015: Halcyon Rising
Failure, Critical Failure and Success
Automatic failure on a roll of a natural 96 to 99: You fail, no-matter how high your skill
Critical success on a roll of a natural 1: Whatever you are doing succeeds, above and beyond a standard success.
Critical failure on a roll of a natural 100: Whatever you are doing fails, above and beyond a standard failure.