Chopping the blinds is a practice when everyone folds, the small and big blinds can mutually agree to take back their blind bets and move to the next hand.
Is this a universally accepted rule? Or Casinos/Card Houses won't allow it?
While chopping the blinds may be widely accepted, it does NOT mean that it's handled in the same way. For example, in most NV cardrooms you can chop with no form or rake or penalty. But in most CA rooms, a chop will still incur a rake, usually taken from the small blind. You should know these ahead of times because it has an impact on your EV during a chop.
Also, players may want to handle chopping differently based on promotions or jackpots. For example, if there is a bonus for quads, a blind with a pocket pair may refuse to chop in that instance because they are in the running for the bonus. So you may run into a scenario where a player is happy to chop one hand but on the next, they may tell you, "I want to see a flop" and not chop. It's common courtesy to see the flop and then one blind returns the money to the other blind when they miss. But again, this will all depend on the room you're in and any special rules that apply.
Blind chopping is typically allowed in most brick and mortar card rooms. Online I am not aware of any card room that has gone through the trouble of implementing a blind chopping feature.
Roberts rules of poker has formalized allowing of chopping blinds.(Section two Procedures 15).
Chopping blinds at least in Nevada is possibly against gaming regulations which do not allow the chopping of any pots accept in high low games. This may also be generally true in most poker regulatory regions. Roberts rules also state that chopping pots is prohibited. When ever you have a bet and a call which technically is what a big and small blind is, splitting the blinds is indeed splitting the pot.
It is likely that chopping blinds is technically against the rules everywhere, however it is a rule that the poker industry long ago threw its hands up on enforcing.
So yes you can chop blinds, is it against the rules, maybe, maybe not but nobody really cares anymore.
I wish some day that people start considering chopping blinds the hustle of tight players to play tighter and stop chopping blinds. I wish poker rooms would stop allowing blind chopping. I doubt that will ever happen.