We play they only participate in the battle if they use their ability. No ability used didn't participate. Not sure what the official rules are.[/q
I'm not sure either. I don't see this in the answers from Corey document.
Looking at the core rules, I read this in the part of battle about retreats (page 21):
[q="Runewars rules"]Units in the area that did not participate in the battle (i.e., were not placed next to the player's faction sheet and remained in the contested area during step 2) cannot retreat and are destroyed.
In the Banners of War rules, it says,
Banners of War rules wrote:
When a standing commander is in an area in which friendly units are resolving a battle, he provides the ability listed on his Commander card.If the player loses the battle, his commander must retreat along with his retreating units (as if the hero were a unit).
So, even if a player has no participating units (because they were already routed), that player would still be considered to have lost. So would the hero retreat?
I'm kind of thinking not because of this scenario. What if the commander happened to be at a friendly stronghold in which no friendly units are present. You still control the area and the enemy would still win the battle, but because there are no friendly units, it's clear that the commander would not be involved with the battle. I'm inclined to think that if no units are placed next to the faction sheet, the commander does not participate.
These are all just my interpretations.