If you have no red runes up, can you still shoot with fire rune?

You might roll up a panic, or trigger surge effects. With the Vantala skirmishers with Maegan (adding a blue, hunters guile to swap for white) or Barron V in a unit (swapping for white then adding a blue), both could trigger significant surge effects.

Yes, it is still an attack that triggers all other effects that might be on the card. You've got some good examples there.

In addition, you're obligated to make the attack even with no Unstable. This means if your only viable target is engaged, you can't opt to not take the shot in order to dodge the morale test for shooting a unit engaged with a friendly.

Unless, of course, you have other skill options at your disposal.

Really? I thought 10.3 kicked in if there were no unstable runes:

"If a game effect removes dice from an attack such that there are no dice to roll, the attack is canceled."

You always roll your red die for a Fire Rune attack. The runes tell you what to replace your normal threat with. So no, you haven't removed the last die for the attack.

7 hours ago, Parakitor said:

Really? I thought 10.3 kicked in if there were no unstable runes:

"If a game effect removes dice from an attack such that there are no dice to roll, the attack is canceled."

I think you may have confused Fire Rune with Ankaur Maro's ranged attack.

8 minutes ago, Budgernaut said:

I think you may have confused Fire Rune with Ankaur Maro's ranged attack.

Oh, that's right. Fire Rune rolls dice with 0 threat if there are no unstable runes. Got it.