Units from different armies, but which share the same alignment (i.e. either Order or Destruction – non- aligned units are always treated as being suspicious allies, as detailed later) are considered to be Trusted Allies when they fight in an alliance.
Trusted Allies follow the rules for Bound by Blood except that they:
Cannot be joined by allied characters.
Cannot use an allied General's Inspiring Presence rule.
Cannot use an allied battle standard's Hold Your Ground rule.
Magic
If the alliance contains only Trusted or Suspicious Allies, power and dispel dice generated by the Winds of Magic can be split between the allied armies as the controlling players wish, but this must be done before any spellcasting is attempted. Dice generated by channelling must only be used by the channelling Wizard's army, as must any dice generated by magic items, special abilities and so on.