- Don't camp excessively
"Camping" is when you hover near to a weapon respawn point, loading up on the weapon's ammunition and fragging anybody that comes to get it. This tactic has been considered extremely bad form in first-person shooter games since the days of Doom and Quake, because it is an extremely unskilled way to rack up frags. If you camp, you can be guaranteed that people will hurl insults at you, go out of their way to frag you, and generally reduce the quality of the arena you're playing in. The bottom line is campers don't win; camping will get you some easy frags, but any good gladiator will be able to get more frags by actually doing the work. Q3DM12, with the BFG room, is a particularly bad example of a camper-friendly room, but even with an optimally placed camper, an experienced gladiator can take him out with a try or two (even without the BFG).
Resorting to nothing but camping will leave you resented, a prime target for everyone else, and at the bottom of the heap. Do it at your own peril.
- Avoid BFG arenas if you don't like them
Many gladiators consider the BFG an abomination, and prefer to play without it. The BFG makes it possible for even relatively unskilled players to rack up a few frags before getting dispatched. Unfortunately, the players who despise the BFG tend to play in arenas that contain the BFG (among the standard maps, that's Q3DM12, Q3DM14, Q3DM15, and Q3CTF4). What's more, they tend to extend their code of ethics to others; they expect everyone else to refrain from using the BFG. Since the BFG is a standard part of Quake III Arena, this is a rather unreasonable request. If you don't like the BFG, don't use it, and live with other people using it. If you don't want to use the BFG and don't want others to either, then avoid arenas that contain the BFG (there are only four), or play on dedicated servers with mods that remove the BFG. Calling people "BFG whores" doesn't accomplish anything except make you a sore loser, whether you choose to avoid using the BFG or not.
If you prefer not to use the BFG, either don't use it and live with others using it if they so choose, or simply do not play on arenas which contain the BFG. Yelling at people for using an intrinsic part of the game accomplishes nothing.
- Don't shoot talkers
When the talk bubble [;) ...] appears above a gladiator, they are either typing in a message to say or are otherwise indisposed (such as changing settings). Don't shoot people who are talking, or at the very least stop firing once you notice the talk icon. It is considered bad form to frag someone who is clearly indisposed, as they offer no immediate threat to you. By the same token, though, don't try to use talking as a way to get out of hairy combat; that won't fool anyone. One can also avoid being fragged while talking by being careful when one choose to talk; don't stop to type something when you're being pursued, or in a room where there's a lot of fighting going on. Don't frag talkers, but don't talk when you're under fire or in a place where you're likely to get accidentally fragged, either. The converse is true; if you're talking and another gladiator comes by and passes up on shooting you, don't come out of talking and shoot him in the back! Using macros to automate quick responses ("Yes," "No," "Good shot," etc.) can also reduce your exposure to talk-fraggers.
When a gladiator has the talk icon above their heads, don't shoot them, or at the very least stop shooting at them. But don't use talking as a way out of a skirmish you're losing, and when talking don't immediately shoot people who were kind enough to pass you up.
- Don't get team powerups if you don't plan on using them to their fullest (Team Arena)
On each Team Arena map, there are only a finite number of the different kinds of team powerups, and once in use, its user has to die before the powerup resets to its spawn location. Don't pick up the more powerful team powerups if you don't plan on using them; there's nothing less likely to cause frustration among your teammates than someone who takes the only guard powerup and then wanders around behind his own base exploring.
If you don't plan on making full use of a team powerup, leave it for someone else who will.