FF3. Roll to resolve the firefight
Both players: Roll a D6 and add your firefight bonuses to the result.
The player with the highest total score wins the firefight.
If the total scores are the same then the outcome hangs in the balance! Place one Blast marker on every detachment in the firefight, and then proceed again from FF2. Work out firefight bonuses.
Optional two D6 method for assault resolution
In Epic 40,000 Magazine issue 8, page 6, game designer Jervis Johnson recommended that players roll two D6 and use the highest of the two results. If you use this option then note that any game effects that allow you to re-roll the combat resolution roll allow you to re-roll one D6, not both.