So you think that Quake 2 is a fair game eh? Well there are a few 'ethical' issues which I will point out. Although there are no rules for them its only polite to do as so. Going against Quake ethics is also know as being cheap (but whats wrong with that anyway?)
-Escaping from a battle
Escaping from a fight is cheap. So? I wrote a whole section on ESCAPING! Still some people find it cheap that you run away from a battle because you're half dead with a blaster.
-Shooting someone once they have respawned
Yeah this is pretty cheap. But only in rare occasions will you have the chance to do this. Splendour the moment when it comes.
-Camping
Camping isn't that bad but to be a 'fair' quaker, especially in one on one matches. Camping is ethically unacceptable
-Collecting armour
My favourite hobby. Armour provides extra protection from those nasty rockets. Of course this is unethical as well since armour can be stored up and so you can become quite invincible (Hint, nudge, nudge)
-Collecting health
Less cheap then collecting armour but still cheap. How else is someone going to kill you when all you do is collect health?
-Killing a stationary target
Most times when someone is standing around it means they are chatting. Although this is a free frag for you, it can sometimes turn out that the other guy has a BFG and was just waiting for you to come around.
-Shooting someone in the back
Although old people hate being shot in the back because they are not alert enough to respond, it is cheap to shoot someone in the back and kill them as well. The ethical way would be to shoot someone, allow them to turn around and then have a clean fight with them.
-Looking at someone else's screen
This is not unethical but downrigt cheating. Of course you can't really be penalised for it but when you look at somelse's screen make sure in your screen nobody is shooting at you.
-Quitting out of a game you are losing
Quake is not a game for quitters. If you are losing, don't quit and don't be frag bait. Try to win your way back to the top. This reminds me of a story about the map 'Frag Pipe'. I was in fact coming last in the map with 12 frags (the first having 16 frags). Using my skills I just won the match. Never give up. (Quake can also be philosophy for life)
-Quitting out of a game you are winning
I don't know why'd you'd do this but it happens.
-Jumping around all the time
Filling someone's soundblaster with 'Hmpph' can be extremely annoying (and effective). Not only does this silence your footsteps from the direction you are coming from but it pisses off snipers at their nests. This is an unethical practice.
-Throwing grenades around for fun
My other favourite hobby. Highly unethical but its funny when you hit someone (and score a frag)
-Complaining about unethical practices
Complaining about repeat unethical practices can annoy people: 'Stop collecting your stupid armour' or 'Stop shooting me in the back will ya?' typed in the chat box can lower the morale of those guilty (and score you frags by doing it yourself). This is unethical as well.
If it seems to you that I've written a list of 'cheap tactics' instead of Quake ethics, then you're just cynical of Quake.