Damage ControlThere are various different things that will affects how much damage you take or inflict.
Random numbersThe Rocket Launcher will deliver a guaranteed 100 points of damage per shot - however, a random number is generated between 1 and 20 for additional damage.
Surprising the enemyIf you attack an enemy that is idle (hasn't been alerted) your weapon will do double the normal damage.
Easy skill levelWhen the game is played on the 'Easy' skill level, all damage received by the player is reduced by half. But this obviously doesn't hold for deathmatches...
Falling damageThis is the amount of damage sustained from a fall, which is exponentially based on the distance you fell. The actual formula is
Environmental HazardsLava, acid and toxic water will cook you for every frame you're within the liquid. Armour seems to help. Lava is very deadly killing most players in under two seconds, while toxic water only donates 2 points of damage per frame. Remember - fall in the soup, loose a frag - so if they are stuck and you kill them, you will be doing them a favour, although you do get an extra frag... Hmm... Aw, just blast em...
There are other hazards in the game that will cause the player damage including exploding walls, electrified floors, barrels and laser beams. A properly used barrel can often be more effective than your actual weapons, and a laser beam will gib any player on contact.
DrowningIf you stay underwater too long, you'll sustain damage. The damage you receive after running out of oxygen is as follows:
So the idea with water is 'Stay in it for as short a time as possible'. If there are them nasty fish things there, either blast them faster than a psycho in a junior school, or leg it out of the water, whatever's quicker. And as you move at a slower speed in the water, you are way more vulnerable - watch for guys behind you... However, there will often be a prize for you taking the risks (e.g. in Q2DM1, the railgun room)