Dodging
Marines have the ability to dodge the strongest projectile heading their way. When a projectile is roughly heading towards the marine and is within 384 map units of them (By default, see below). They will check if the projectile is fired from a friendly NPC or player, if it is, they will only dodge it if it does as much or more damage than half the marines' health. Otherwise, they'll dodge it regardless of how much damage it does. They don't try dodging projectiles that won't harm them. Also, if the projectile is coming from behind them, they will only be able to detect and avoid it if it's within 128MU of them or so.
The distance in which marines check for projectiles can be changed (Or used to turn dodging off entirely for the specific marine) with User_DodgeRange.
If the marine decides to dodge a projectile. They will do so by jumping to the left or right of it, depending on which direction is AWAY from the projectile, however, if the marine isn't set to fast (Through +ALWAYSFAST or sv_fastmonsters), they also have a small chance of making a mistake and jumping towards the projectile accidentally.
However, they also check if each direction they're jumping at is actually valid, for example, if there's a wall to their left, they'll only jump to the right, because that's the only direction they can actually jump to, if the space they're in has both their left and right blocked, they will not try dodging at all since they can't.
Note: Detecting the actual vanilla Revenant rockets might be finnicky due to John Carmack implementing its' homing behavior in the worst way he could've thought of. This mainly works well with projectiles actually marked with +SEEKERMISSILE.
If the incoming projectile the marine has decided to dodge is detected as a homing projectile. Then instead of jumping out of its' way, the marine will try retreating from it to escape. If the projectile gets too close while running from it, they might try to duck under it, to try and throw it off.
If a marine is sitting behind cover, they can still dodge by just hiding behind cover again until the incoming projectile goes away.