Mercenary Mech Warfare is a heavily modified version of Craft Text, a mostly diceless, statless roleplaying system. There is little arithmetic. A character is a concept, a background, a condition, a list of Abilities, and the Gear they carry; outcomes follow from those fictional facts.

Abilities are what let a pilot attempt what others cannot. Tech keeps a mech flying — repair, engineering, hacking and drones — Physical covers the body under stress, and General covers command, negotiation, professions and hard-won knowledge. Specialist disciplines push each field further, from ace piloting to chief engineering. Many form named chains, so Chef leads to Expert Chef and then to World Class Chef.

Equipment sits in one slot per body location, and each slot only offers gear that belongs there. There is no combat subsystem or advancement track because the Game Master handles both through the fiction rather than arithmetic.