Combat - Defenses and Attack rolls

Mechs and their human pilots share the same defenses: AC, Fortitude, Reflex, and Will. Most times, the attacks against a mech will be rolled against its AC.

When thinking about AC and attack rolls, it's important to realize that for every 2 hexes a mech moves during its turn, it adds +1 to its AC and -1 to its attack rolls until the start of its next turn.

AC = Mech's AC + 1/2 Pilot's level + Pilot's Dex modifier + Mech's special bonuses +/- Movement modifiers

Attack Roll = d20 + 1/2 Pilot's level + Pilot's Dex modiifer + Mech's special bonuses +/- Movement modifiers

Resolve attacks accordingly.

Damage is always a fixed amount, based on the weapon that hits the target, just like current Battletech rules. 2d6 is rolled in the event that a critical hit is scored on a natural die roll of d20, or if a mech suffers internal damage after it's outer armor has been completely destroyed in a section of its body. In such cases, the 2d6 roll is used to determine what kind of critical hit is scored. The damage from the initial hit is still fixed and based on the weapon that hit.

If a natural 20 is rolled on an attack roll and the target still has outer armor on the section that is hit after damage is subtracted, then it is not an automatic critical. The attacker rolls 2d6 and must roll higher than 6 or 7 (whatever the threshold is on the current rules) to determine if it is even a critical hit. So if they roll low, there is no critical hit. This is the same mechanic as determining a critical hit currently in Battletech.

If a natural 20 is rolled on an attack roll and the target has lost all outer armor on the section that is hit and takes internal damage, then it IS an automatic critical. The attacker rolls 2d6 and consults a different table (one for "bloodied" mechs) and determines what the critical hit does. So in this case, the critical hit is always a critical hit.