New Rule: What Breaks First?
When two opposing forces meet (such as, say, a dragon smashing into a mast), both will take damage as though one fell onto the other until either:
1. The damage dice of an equivalent fall have been rolled, or…
2. One (or both) of the “forces” breaks (breaking meaning either the physical breaking of an object or the pulverization of a living/unliving being)
Both forces take the same amount of damage, adjusted for potential hardness or damage reduction (falling damage being considered bludgeoning damage).