Just for kicks, I compiled my first 12 rules of TERA. These are meant to be humorous, yet true. Everyone is free to add their own rules, and if I like it I'll add them to the list.
Rule of TERA #1: The amount of defense female character armor provides is directly proportional to the amount of skin it reveals.
Rule of TERA #2: The item you are running an instance for will not drop until after you have already acquired it.
Rule of TERA #3: The highest roll on the item you wanted most will always go to the worst player in your party.
Rule of TERA #4: If there's a narrow passageway you must pass through, there is always an enemy or a BAM blocking the way.
Rule of TERA #5: You will only be successful when enchanting above +5 when you care about it the least.
Rule of TERA #6: Every time a Hyena jumps through you, BlueHole laughs hysterically at you, then God kills a kitten.
Rule of TERA #7: The instance matching button is the "I didn't need these crystals anyway" button.
Rule of TERA #8: For a dps class, the estimated time remaining in the instance queue is not in minutes, its in hours.
Rule of TERA #9: Women don't play female characters. They play Elin.
Rule of TERA #10: The teleport masters want you to get ganked. They always teleport you to channel 1.
Rule of TERA #11: If your instance party waits more than 30 seconds to start, the Slayer will attempt to solo the instance by himself.
Rule of TERA #12: Talking in area chat on a constant basis requires an IQ of less than 90, or less than 80 if its LFG chat.
Rule of TERA #13: The tank in your instance matched party waited 0.2 seconds to join you, and isn't afraid to repeat that process to join someone else because you looked at him funny.
Rule of TERA #14: When tanking, the melee classes will stand on both sides of you so you can't strafe when the BAM decides to level your skull in.
Rule of TERA #15: As a melee, the moment you decide to use your strongest attack is the moment someone steps in front of you, making you hit only air.
Rule of TERA #16: As a Mystic, the quantity of motes you place is inversely proportional to the likelihood that your party members will consume them.
Rule of TERA #17: If you wish to negotiate a price with someone through the trade broker, they will miraculously be AFK.
Rule of TERA #18: Every time someone wishes to negotiate one of your sales, they will do so in the middle of your dungeon boss fight, when you can't respond.
Rule of TERA #19: The other members of your instance matched party never have any Arunic Panaceas.
Rule of TERA #20: Zyrks are made of paper-thin glass; they always break first.
Rule of TERA #21: Teleport Jaunt only cools down out of combat, when you need it the least.
Rule of TERA #22: Selling a high-value item at the Brokerage will net you several new people to put on your block list.
Update 2:
Rule of TERA #23: If you are winning a GvG battle, your opponent will miraculously find a safe zone before you can finish him.
Rule of TERA #24: When farming a low level instance solo, the item you want to drop will only do so if you run the instance on a different character.
Rule of TERA #25: The last minion of the group is the one that has no hit detection box.