Rule 2

Rule 2: When someone is acting, no one may speak to them.
This includes if someone is in the middle of a skill challenge (where the player needs to make a number of consecutive skill checks to succeed), or in the middle of combat. Basically, if someone is deciding if they want to turn left or right, another player saying "Hit the one on the left!" is not acceptable. This is considered 'coaching', and I should be the only one coaching players on their actions. Talking with other players outside of your initiative is completely acceptable and actually encouraged. Form strategies. Make plans. But do so when it is not your turn, otherwise you run the risk of slowing down the game play. Which brings me to the next rule ...