I think I know the answer to this, but I wanted to confirm. Sorry if it was already asked... I don't think it has...
The rules are very clear that if you play multiple event cards that confer special abilities on Units, special abilities with the same name do not stack.
However, what about cards that do not confer special abilities? I imagine that these could "stack"... but I wanted to make sure. Specifically:
Heroic Feat: If I played 2x Heroic Feat on a single Unit, could I add 4 to their attack value?
Goblin Rush: If I played 2x Goblin Rush, could I move the same units once with one card, and once with the other?