Aces

All Trait and damage rolls in Savage Worlds are capable of “exploding.” When you roll the highest number possible on a die (a 6 on a d6, an 8 on a d8, etc), you get to roll that die again and add the new result to the total. This is called getting an Ace. if your second roll also Aces, you can roll it again until you stop Acing. This is the equivalent of critical hits in other RPG systems.