After reading Tips to be a great D&D player by James Introcaso, I thought I’d expand on it with a few thoughts of my own. His post is really helpful though, and you should definitely read it as it’s quite comprehensive. I view all of this from the perspective of someone who mostly considers himself a DM. But lately, I’ve found myself playing almost as much as I run games.
More than anything else I will say below, be polite. D&D is a social game and you need to be able to interact appropriately with other people. Respect their boundaries, treat them with dignity, and remember that everyone has their own baggage. For some reason, RPGs can bring out some really creepy behaviors from DMs or players. Speak up when something is really inappropriate: if somebody else has clearly made another player uncomfortable, support the person who has been put on the defensive. When I run games, I set very clear expectations, but sometimes a DM won’t notice or can even be part of the problem. Do your part to make everybody at the table comfortable and the rest will fall into place.
Occasionally I find myself jonesing to sit in the DM chair again. So if you normally play as the DM, then resist the temptation to impose your style on another DM. On the contrary, I make notes to myself about what I can learn from the other DM’s style – even the newest DMs do interesting things I might enjoy trying out later. I can’t emphasize this enough: even when watching D&D games on YouTube, I literally take notes on cool techniques or approaches. Nadja Otikor on Misscliks Risen in particular has a wonderful way of encouraging the players to help build the scenes, for example.
As a player, definitely come prepared. Have your character sheet ready, your dice out, and (if appropriate to your game) your mini on the table. This also includes showing up on time. Some of this is basic etiquette, but unlike a class or a meeting at work, your gaming group likely cannot or will not proceed until everyone is accounted for and ready. Don’t waste everyone else’s time, especially in a group of adults who’ve carved out time from the rest of their lives for a bit of fantasy escapism.
Know your class: it’s not the DM’s job to know what your spells do or how your features work. That’s on you. Your DM might know them very well, but if she’s never played that class or subclass before, then some of the details might elude her – and very few people have all the spells memorized. This might mean preparing spell cards or having notes, and it definitely goes along with knowing what you will do before your turn comes around.
Don’t be a rules lawyer. If the DM asks you how a particular rule works, then by all means help them understand what the official rules are, but always remember that the DM at the table can overrule anything if it doesn’t make sense in the circumstance or the group just wants a different feel.
Obviously this list isn’t comprehensive and I’m probably missing some things, but hopefully this helps folks find ways to help everyone else have more fun at the gaming table.