In Mech Retriever, there are currently 14 different heroes. You are dealt three and choose one at the beginning of the game. But what makes them worthy of being called Heroes?
Heroes come in all sorts of flavors, ranging from conventional classes like Gunner or Pilot to unusual ones like Geologist or Executive. But what they have in common is they provide you with two abilities to give you an edge over the competition: an Active Ability and a Passive Abilities.
Passive Abilities are usually fairly simple–they give you some small, static benefit that is always active. Examples include +1 speed from Peter Gonzalez, +1 Damage from Raquel Lopez, or +1 Crystal on first Crystal pickup each turn from Ginivieve Romano. Some of them can be used optionally, but overall Passive effects are pretty small effects.
Active Abilities are special, and more powerful. They can only be used once each Battle phase, and you can only use one per turn. Examples include doubling the range of all your weapons this turn from Michael Jones, or spawning 1-6 additional crystals in the current sector from Ginivieve Romano. These exciting abilities are so powerful you can build entire strategies around them.
So when your mech is deployed, it has three actions each turn: Move, Attack, and Use an Active. At first, you will only have 1 Passive and 1 Active, but that’s where Special Parts come in–Special Parts will usually grant you either an Active or Passive ability.