There are 6 factions of mercenary miners (Mercenaries) in the game. Each faction is represented by a different color and symbol. Each Mercenary has a level, indicated by a number from 1 to 4 on the card, and every Mercenary has a special skill, either an action or an in-game effect, that is described in detail in the text box at the bottom of the card.
The higher the level of a Mercenary, the better its skill.