In Vegas blackjack, is one permitted to bet on any player sitting at the table? The process that was suggested to me was that anyone can walk up behind a seated player before the hand is dealt and match the initial amount of chips that the seated player has wagered. If the seated player increases their bet via splitting/doubling down etc then the person matching must continue to do so or else forfeit their bet.
Is this standard?
I’ve never bet on someone else’s hand in blackjack, but I have done it playing pai gow poker. I have had strangers bet on my pai gow hand when I was hot.
Honey, you’re still hot in my book.
:smack: You know I meant “on a hot streak.” 
But since the OP asked, here is how you do it. I can stand behind a player who’s doing well, and tell the dealer I would like to place a side bet on him/her. I place my bet to the side of the player, or wherever the dealer tells me to. If the player wins, I win; if she/he loses, I lose too. But I can’t remember if there is a minimum bet or if a matching bet is required… it’s been a long time.
I’ve had no problem betting for (with?) others when I’m sitting at the table. I’ve been allowed to cover their doubles and splits, too. I can’t imagine the casino would ever turn away a bet unless they had to.
What if the person playing objects?