So I was thinking, what things cause people not to play in some games?
My personals include:
Drinking alcoholic beverages or smoking at games.
Having romantic relationships between players/GMs
Playing longer than scheduled.
I'm sure there's others, but those are my three. Try not to make anything personal in your responses, there's no need to be derogatory.
Here's mine:
1. DM's who want to run "fast and loose" which usually translates, "I've never taken the time to read the rules, so I'm just going to wing it." Read the rules for the game you're going to run or break out a boardgame. While I won't rule lawyer a game, I want to be able to do some things that are normal for a game, like roll the appropriate dice for iniative, do the range of allowed actions, etc. For example, we had a DM at a con who did it "fast and loose" on D&D 3.0. So we all know that init is d20, put it order, and then standard action/move action. The DM wouldn't pay attention and would cut a player's action out as he switched gears. The same player would declare a normal action like retrieve an item from pack (move action), but the DM ruled he couldn't do it in while there was a combat going on, etc., etc.
2. DM's who make up adventures on the fly. Sure, there are DM's who claim that they are awesome story tellers, have created interwoven plots, and have made their players have their characters to feel rage, anger, a sense of justice, loss, etc. far better than any movie or book. That's great, but all the DM's I've played with would blow 2 hours to role play buying a suit of armor, encounters are random and don't make any sense, there's no sense of plot, and just wandering around lost. Write some notes, create a plot, pick encounters that make sense and get going.
3. Playing favorites. I had a DM who I regularly played RPGA classic campaigns with at a bookstore and everyone had to rate the other players. Two players were always rated the highest (given 5's) and everyone else was rated very low (given 1's and 2's). Consistently. I think only one session did I score a "3" average on one of my games out of that group.