Sometimes people do things that simply make no sense. As a dungeon master I put in a lot of work into my games to try and create a great experience for my players. After putting so much work into a campaign, and each quest, encounter and NPC, every now and then a player comes along that makes you want to tear your hair out. I've had some experiences at the table lately that have really clarified my thoughts on this matter. If you are a player and you want to completely piss off your dungeon master, here's how to do it.

Don't read the rules. Dungeons & Dragons is an in-person social game. It's one of the things which makes it so much more fun compared to a video game. It's okay to not be a storyteller, min-maxer, or actor. But if you're going to play this game read the freakin' rules. Wizards has even put out a free basic version for those too cheap to spring for amazon's reduced price of their books. If you show up to the game and have no clue how to play because you didn't understand certain rules, I can forgive that. You tried and put in the effort. If you read the book and can't remember a single word you read, fine. At least you tried. But if you have no clue what's going on because you didn't read the rules you are automatically on my shit list.

Websurfing/Text during the game. If you're so bored that you need you're phone to distract you, why are you here? If you have kids at home, or family/significant others you want to be available for in case of emergency, that's completely understandable. If you're on your phone when it's not your turn and then have no clue what's going on in the encounter because of it, you've pissed off your dungeon master. Even worse, you take out your phone automatically because the dungeon master starts to read a 30 second description. In my game, everything is created by me, including descriptions. Show a little respect to the work I've put in as a game master so you can play.

Do you want to take this to the next level of weird? Be a player in a game, take out your giant phone, and start surfing the web for porn. At the table. With people to either side of you. Clearly visible from across the table to everyone with eyes. Yep.

Have a non-D&D conversation while the DM is talking. Are we 4th graders? For all the same reasons as above this is wrong, made worse by the fact that the inattentive players are no longer silent but actively interrupting the game.

Tell everyone they need to hurry up the game so you can go home. Before the predetermined time slot for the session has finished - with no prior warning, multiple times. Yeah, this happened.

Show up unprepared. As a player, there is only one thing you need to worry about: you're character. The Dungeon Master is creating an entire campaign for you, and you're burden to play is to make just one character. When it's too much for a player to show up with a completed character, or worse show up with a blank character sheet, it's just rude. There are so many ways around this. If you can't make a character have a friend do it for you, or ask your DM and give him even a little more work. I've obliged to that request in the past. I've put together character concepts for other players. I will not fill out a character sheet for them. That is the minimum amount of effort required to play a pen and paper game. You need to put pen to paper. Even if you are the least imaginative person in the world and can't make your own backstory, you have to at least fill out your own character sheet.