Ok I have a question about cumulative crit effects. If a marine takes enough damage to go say 3 over his wounds threshold in a single attack would be suffer only one level of fatigue from the crit effect or would be suffer the effects of each level of fatigue before it as well.
Also power armor allows marines to ignore crit effects for a number of rounds due to the combat drugs. What if the effect is something like severed limb? Does the limb fall off after the drug wears off?
Do you mean the character in question had fatigue prior to suffering the 3 crit? Or do you mean he also suffers crit effects 1 and 2 in addition to 3.
In the first case: yes all fatigue is cumulative, this is how you get knocked unconcious: taking enough fatigue to beat your TB. As for fatigue penalties, you only ever suffer a single -10 from fatigue irrespective of the amount of fatigue you have.
In the second case: NO, you do not suffer the lower levels of crit damage when you suffer a crit hit. You only suffer the crit damage the last hit took you to. It is possible to get hit and go to 1 crit, then take 2 more points of damage and go to 2 crit, and finally take another 2 points of damage and get into 3 crit. If this happens you do suffer all 3 levels of crit as seperate attacks took you to each crit level. If you only took 1 attack which put you straight to 3 crit you ONLY suffer the effects of a level 3 crit.
Combat drugs allows you to ignore non-physical damage effects.
Stuns, fatigue, or disorientation are ignored for the number of rounds you roll. These effects apply immediately so it is possible to nulify crit effects by having combat drugs work longer than the crit effect (for instance you get stunned for 2 rounds but roll 3 turns for combat drugs). Combat drugs also ignore these effects even if they existed before going crit and any new effects applied while combat drugs are still working.
Physical results such as slipping on blood, loss of limbs, or being knocked to the ground are not prevented or mitigated by combat drugs. Even if you used all 6 doses at once, your arm is still chopped off when its chopped off.