The heroes of your campaign aren't likely to sit idly by while war rages around them. Fighters may want to charge the gates, wizards unleash fireballs into the masses, and a gallant knight may ride his trusty warhorse directly into the enemy formations. Those who want to get involved can dramatically affect the results of the battle. Have each character make a Fighting, Shooting, or arcane skill roll (their choice) each action and consult the Character Results below.
Modifiers: Add or subtract the number of tokens difference between the heroes' side and their opponent. If the enemy has 8 tokens and the heroes have 5, for example, the heroes must subtract -3 from their attack rolls. Also add +1 to the roll for each Rank a hero has above Novice to account for his various Edges and abilities that aren't reflected in a straight skill roll.
Character Battle Results
Ammo: If it's important to track, each round a hero enters the fray and uses his Shooting or an arcane skill (such as Spellcasting), he expends some of his ammunition or Power Points.
Arcane types use 2d6 Power Points per round. Characters with ranged weapons use 3d6 shots for ranged weapons (triple that for weapons that usually fire bursts or full-auto). If the hero winds up without any ammo or Power Points she'll have to change tactics for the next round.
Savage Worlds Deluxe Edition p. 106