Well, this is some nice stuff we all should know. You can actually attack/deny an allied hero! But… conditions apply.
The allied hero should have less than 25% hp left.
It should suffer from either of the following buffs:
– Venomous Gale
– Shadow Strike [not Viper Strike]
– Shadow Word [hostile]
So, its good if you deny an allied hero so the enemy doesn’t get the gold, but first make sure he’s going to die of the spell! Many a times players deny allies who actually would have survived with very low hit points.
There are a few spells also to deny allies. These are namely Toss, Bloodrage and Nightmare unless I’m forgetting some.(Note that these will not allow allies to ‘physically attack’ allies but they’ll deny them by their own damage!) 🙂