a) You will always be safest on your own, if you've been stuck with another person (in a single player game) you can usually guarentee that someone's going to die/be injured and soon.
b) There is no such thing as 'overkill', only 'just about enough-kill'.
c) Don't be a red shirt, don't be the first person to enter a mysterious and unexplored room/building and don't volunteer to 'split up to cover more ground'.
d) If your friend is dying, don't put yourself in danger to rescue them, you'll probably just end up joining them in Hell(sometimes the kindest thing to do is blow a kiss goodbye and walk on).
e) If all else fails, nuke it (or pull out a rocket launcher/plasma cannon depending on the game).
b) There is no such thing as 'overkill', only 'just about enough-kill'.
c) Don't be a red shirt, don't be the first person to enter a mysterious and unexplored room/building and don't volunteer to 'split up to cover more ground'.
d) If your friend is dying, don't put yourself in danger to rescue them, you'll probably just end up joining them in Hell(sometimes the kindest thing to do is blow a kiss goodbye and walk on).
e) If all else fails, nuke it (or pull out a rocket launcher/plasma cannon depending on the game).