In a lot of games of roll-under you can max a stat by specialising in it, making the roll auto-succeed.
Example: I played an angel of Novalis with a high will. As an after thought I bought Aikido (lots of people in the player groups I play with are Jitsukas, and give a few of their characters Jiu-jitsu as a skill, I thought I'd break the mold), to 4. That mean my roll to attack with Aikido was 12, in a game that's Roll-under with 2d6. I couldn't fail.
I tried not to abuse this, but I'm sure it must happen. How can you counteract this in In Nomine and other games with a similar mechanic?