If a game allows you to run it twice, 3 times etc
What are the procedures
Both players have to be all in 1st, then if one asks the other do u want to run it twice
Is it a simple yes or no or are the players allowed to disclose both their holdings and then decide to run it or not run it?

Also what happens if
3 players are in a pot, player a is all in, player b and c continue betting and create a side pot, further betting continues and both players are all in

Now there is a main pot with £1000 and a side pot £800.

Both players b and c agree to run it twice, player a says he does not want it run twice
What happens here?

Is player a effected?

in this case they usually cant run it twice, or, at a homegame, you could deal once and ship full mainpot to player A if he wins and the half of the sidepot to the sidepot winner (or half of the full pot if player A loses the first run). then deal a second time and ship second half of the sidepot (or half of the whole pot) to the winner of that run.
never had smth like that, but these seems to be the only logic possibilities.

for more detailed answer ask a mod to move the thread to the "THEORY" forum.