I've done some searching on the forums, but all I've found is how to make a goblin merchant that sells to a specific player.
I'm trying to make a merchant that will sell to anyone on his team, but will not sell anything to those from the other team. One way to do it, of course, is create a trigger that removes items, refunds money, and gives an error message to enemies buying stuff. I'm sure there's a more eloquent way, though. | 
