Can you tell me the "official" rules about live straddles?

Is it permitted only one straddle? (the next after big blind) In my country we can do more straddles...

Example:

SB 1$
BB 2$
optional straddle 4$
optional straddle 8$
optional straddle 16$
optional straddle 32$

cheers

Generally, in the rooms where I have played, you are just allowed a single optional straddle from the Under the Gun position.

Just one allowed at the River Rock.

Depends on the casino. Most casinos will only allow one live strattle. The reason behind this is that it just gets too confusing for the dealer and can actually slow a game down.

There are many ways a live straddle is played, the easiest one is just a 3rd blind. The usual UTG player will put out double what the big blind is and be last to act preflop.

Some casinos allow the UTG to straddle for as much as they want, a recent 1-2 game had some idiot who would straddle for $162 all the time, it was idiotic, but no one could stop him, and why would they if you pick up AA, KK, QQ AK or maybe AQ or JJ wouldn't you call in late position?

There are two other ways I have seen it, where anyone can straddle from any position and "buy the button" pre flop. I have also seen people place dead bets from out of position, this is lame and really no fun.

Hope that helps.