I have been toying with a few free form style RP games and have trying to come up with a simple system rule to deal with conflicts.
Taking a bit from the 7th sea system, there would be three tiers of baddies.
Rank and file
Villains
Super Villains
The "alpha" rule is a d10 + a possible modifier and the two sides compare numbers, higher wins. Ties roll off until one side wins.
The modifiers are GM given as an RP reward.