Two hands. `BattleArmor.canMakeAntiMekAttacks` is not the weight class alone: the suit must be lighter than a heavy one, not be a quad, and have something to hold on with - two armoured gloves or two basic manipulators, or one battle claw, or a magnetic clamp, and a glove is no use at all past light. That is why a Tunnel Rat with a glove on each arm climbs and one with a single manipulator does not. Suits carrying MegaMek's own list go from 1,130 of 1,188 to 1,184, and a `.blk` now records which arm a suit's equipment is on rather than discarding it. One deliberate departure: upstream reads `basic > 0` where this reads `basic > 1`. Ninety suits carry exactly one basic manipulator and MegaMek gives none of them the attacks, so the answers say one hand is not enough whatever the bytecode says, and the answers are what helm is measured against.