This week, I got the modular effect system working in GearHead: Caramel. This is pretty much the same effect system as used by Dungeon Monkey Eternal, but generalized and expanded to handle the GearHead rule system. The two effects needed for a basic attack (AttackRoll and DoDamage) work, and there is a new option to target more than one tile with a single action (which will be useful for burst fire weapons and missiles).
Weapons will generate their list of effects dynamically. It will be possible for a weapon to have more than one effect- for instance, a railgun can be fired in either single shot or burst fire modes.
This also opens the door to non-physical attack effects such as electronic warfare.