"D.A.G.G.E.R." stands for "Defense Alliance for Global and Galactic Emergency Response", and the "Alliance" and "Emergency Response" elements drive how the game is played, with heroes needing to strengthen themselves via combos in time to take on the nemesis.
There are two types of combo tokens: empowered tokens and primed tokens. When a hero becomes "empowered", they can later discard their empowered token to add one success to any attribute test they perform. When an enemy is "primed", a hero attacking that enemy can remove a primed token from them to add one success to the attack result, which means more damage dealt.
What's more, each hero has at least one "combo ability" that requires either an empowered token on themselves or a primed token on an enemy to trigger. Triggering these combo abilities comes with an extra benefit: advancing the team-up track, a resource shared by all heroes that's used to pay for "team-up abilities", the strongest abilities in each hero's arsenal.
