How do alliance banners work?

By Darthvegeta800, in Warhammer Invasion Rules Questions

How exactly do alliance banners work?

They provide an Icon for both mensioned factions.

I.E., if you play an Empire/Dwarf Alliance, you'll subtract 1 from EVERY loyality cost of both Empire and Dwarves cards.

So for both? Okay thanks, i suspected as much.