Minimum Standards

Considering all these Annoying People of Gaming, there are a few things that a sensible group and GM should insist on in their game sessions. They all sound obvious, but ask any gamer, they've failed on a couple of these counts many times, and they've left a group or stopped GMing a game or refused to host the game group because they've had too many violations of this.

• Cleanliness. You don't have to be Mr GQ Smooth, but have a shower and put on a fresh shirt. Discover the wonderful modern inventions, deodorant and toothpaste.
• Punctuality. Show up on time. If you know you're going to be late, call the game's host and let them know as soon as you do. Don't call half an hour after game start to say you'll be an hour late.
• Politeness. Look, nerds lack social skills, let's be honest. But say hello to the host's non-gaming husband or flatmates. Chat about the weather, ask them how their work's going. Don't tell them about the latest episode of Star Drek or your comic purchase. Be friendly. Don't hit on anyone in the house. Say "excuse me," when you belch. All this increases the chances of your being welcome in the house again. Once people are grown ups, one of the major things that keeps them from gaming is a spouse who says, "those guys are weird." Try to change that to, "those guys are weird, but nice."
• Preparedness. You don't have to go out and buy $600 worth of game supplements, but every player should have, at the least: pencil, scrap paper, character sheet, dice. (One tip for cheap dice is the regular game stores, rather than the roleplaying game stores; for some reason, the former have dice at half the price of the latter). The GM should have all necessary books and notes, and is in no way obliged to carry spare stuff for unprepared players.
• Don't be an Attention Junkie. Unless you're the only player, the game doesn't revolve around you. Don't nag the GM with endless irrelevant questions about rules and setting. Don't expect the GM to change the rules just for you. There's other players there, too, and they'd like a chance to speak up. In particular, you'll find that younger or female players will tend to keep quiet if there are older or male players present. Shut up for a minute and let them speak up. If they still don't speak up, ask their opinion on things, bring them into it.
• Concentration. You're there to be with the group and game, not with other people and other stuff. If you'd rather watch the football or talk to your boyfriend on your mobile or read your comics, go, do that. Go. Elsewhere. Home. Either that, or put that stuff down and pay attention. Is the game boring? Liven it up! Is the GM spending all the time with the Attention Junkie? Remind the GM you're there, that gives them a sense of urgency in dealing with AJ. Do stuff. Otherwise you're just filling a gaming space that could be filled by someone who wants to game.
• Bring munchies. Nerds eat junk food. Bring whatever is to your taste, and share it. Ask the host for a bowl for the chips or sweets, or a plate for the cookies. Put them in the middle of the table for everyone to have some. Sometimes people can't get to a store before the game, that's okay. What you can do then is to say that the host, or other designated person, goes and gets $2 worth of stuff per person there; at the beginning of the game, hand them their two bucks, and munch away.
• Clean up after yourself. At the end of the game session, pick up everyone's glasses and plates and at least put them in the sink. If there's a lot, just start washing them up. Your host isn't your maid. They've been kind enough to host a bunch of noisy geeks in their home for the evening, the least you can do is clean up your dishes. Similarly, immediately clean up spills, make sure all the cheetos go in your mouth and not down your shirt onto the couch, etc.
• Variety. Every fourth session, someone's nominated to organise a different activity for the group. A different roleplaying game, board game, movie, or whatever. This keeps the group fresh and helps prevent Stagnation.
• Flexibility. If that key person can't make it, everyone meet up anyway and play something else. Your local sports team doesn't forfeit the game because a single player is missing, why should you?