Simultaneous exhibitions - or simuls - are a big part of chess culture. Strong players have taken on multiple players at the same time for hundreds of years, often wowing audiences by winning all of their games. Other players have added twists to their simuls in order to make them even more dramatic; Philidor and Morphy were both known to have given blindfold simuls, an exhibition Magnus Carlsen has also recently performed for television.
If you've never been to a simul, you might be surprised to find out just how much fun one can be. Here are a few things that you should keep in mind before playing in (or attempting to organize) a simul.
Space is Limited
While strong players are often willing to take on as many opponents as are willing to play in a simul, the practical truth is that time and space are normally limited - and thus, so are the number of seats available in an exhibition. If you want to play in a simul, it's important to arrive early to ensure you can get in on the action. If you're planning on giving or organizing a simul, it's important to find a realistic cap on the number of players who will be allowed to participate. When setting the cap, take into account the space you have, how long you want the simul to last, and how many players the player giving the exhibition is comfortable playing against.
White is Wrong
This is not a universal truth, but in the default settings for a simul, the player giving the exhibition will take White in every game. Most players won't get too upset if a player sets up the board to take White instead, but it's always best to make sure before you try. If you're not sure and you need to set up your own board, either take Black or ask the organizer or exhibition giver if it is okay for you to be White in your game.
Move or Pass
During the simul, the player giving the exhibition will quickly move from board to board. Sometimes, they will move instantly; at other times, they will think for a few seconds before making a move. In any case, they will be conscious of keeping up a good pace of play - and you should be too.
Your responsibility is to be ready to make a move when the player giving the exhibition reaches your board. Don't move while they are away from the board, and don't stop and think only when they get back to you. Instead, wait for them to complete the move on the board next to you, come over to your board, and then make your move. If you are not sure about your move yet, simply say pass: most simul givers are happy to allow players a limited number of passes during the game (three is customary in many areas).
Also, if there is an obvious forced sequence during your game, there's nothing wrong with quickly responding before the exhibition giver leaves your board; they may be willing to make their next move right away.
By following these simple rules, you should be able to have a good time at any simul you choose to participate in. Simuls can be an amazing opportunity to play against some of the best players in the world, or just a way to get a game against a strong local player who you'd normally never be paired with in a tournament. Either way, remember to thank your opponent for the game, win or lose. Good luck!