A chess simultaneous display is where a strong player takes on more than one opponent simultaneously. Sometimes this is done with clocks but more usually without, when people must move when the simul giver arrives at their board.
Wikipedia notes GM Donner gave 3 bits of advice for taking part which I paraphrase as:
1. Take care in opening, play something you know well.
2. Play aggressively
3. Don’t be afraid of exchanges, as end games are tactical.
One might add to this…
4. Don’t give up (it means the others have a harder time)
5. Passes – often you get 2 or 3 passes where you can think for longer – use them preferably before you make a mistake rather than after.
6. Write the moves down, you’ll learn something and if you win it will be great to have a record of defeating a top player.
Little advice is around on giving simuls. I don’t claim to be an expert but have stood in for a number of club champions at Exeter chess club over the years.
1. Play the same colour, playing an expert’s moves back against him is an old scam.
2. Lose trouble makers early. Competitive simuls have an 80% target score for record attempts, but either way you probably want to agree a draw quickly against players of a similar level to yourself as time spent beating them is multiplied against you.
3. Play swiftly. Not only does it give the others less time to think you’ll remember the positions better.
4. Don’t waste time. A 3 minute loo break against 20 opponents is an hour on their clock, be properly prepared for the match, similarly chatting. Post game analysis can wait till after all the games.
5. Know the rules. Most simuls are played with a “change move rule” when the person giving the simul can change his mind before he has moved to the next table. You knew that right? Do check before hand and make sure it is announced to everyone, you don’t want bad feelings from exercising your rights.