From TacOps (corrected second printing, old omnibus edition) page 55 on High/Low Gravity, and Potential Damage From Jumping sub-section.
Combat on worlds whose gravity is [u]significantly[/u] greater or less than normal Earth gravity (1g) affects a unit's movement.
(emphasis mine) Is there a cut off? e.g. does jumping in 1.01g require a check? 1.05? Or is this anything other than 1.000 (repeating)?
Make a standard Piloting Skill Roll, applying a modifier for every full 0.5 gravities above or below 1.
... If the roll fails for for high gravity, the BattleMech takes 1 point of internal structure damage to each leg
for every 1 Walking MP lost from its normal Walking MP.
Do Mechs have to make skill checks for jumping between 0.51g (less than 0.5 difference) and 1.49g (less than 0.5 difference)?
How should damage and checks be handled when Mechs have different jump MP from their walking speed and lose walking MP due to fractional gravity increases? A Jenner at 7/11/5j under 1.08g conditions changes to 6/9/5j - walking speed decreases, it would roll each turn it jumps and risk 1 point of IS damage to each leg on failure. A theoretical assault Mech at 3/5/5j using improved jump jets would have no walking MP reduction, so even if it fails the check there is zero damage. Similarly, a Mech at 6/9/6j has no MP reduction and also would not suffer damage. In terms of game mechanics, this seems 'off' - units taking or not taking damage based on ground speed reductions even though they are jumping; and heavier units jumping farther, and not needing checks.
