I play in a small rule where rules are fairly loosely enforced. In this room players will often bring out a stack of 20 chips and either count off their bet "over the line" or just drop out the number of chips they intend to bet before retiring the remainder of their chips to the stack.

It doesn't really worry me but it annoys my buddy and he asked me if this is "against the rules." (Obviously it's not in our room but I guess he just means in a general sense/in most US rooms).

I intuitively assume it's against TDA rules but what's the common rule in most cash games? How's it enforced in rooms you guys play in?

In most rooms I play in it's fine.
A string bet will only be called if you go back to your stacks for more chips.

Different rooms have different house rules. The two most common rules are the betting line (one variation is that the edge of your cards is the betting line) and forward motion. Moving chips (over the line or with a forward motion, depending on the rule) will often commit you to a bet. Sometimes, you are committed to betting all the chips you move. Sometimes, you can cut out some of those chips and pull back the remaining chips. Sometimes, a line on the table is a courtesy line and not a betting line. I've played in rooms with most variations of those rules, so I try to bet in a way that satisfies all rule variations.

TDA rules describe themselves as a supplement to house rules, so I think house rules governing what constitutes a bet are used. Of course, not all tournaments are run with TDA rules.

Your room has a soft bet line. Hard bet line rooms are where anything in your hand when you cross the line has to stay in the pot. Hard bet lines are annoying, all they do is slow down the game. You have dummies fumbling with their chips behind the line, then they stack it up, then they fumble with the chips again across the line. Soft bet lines eliminate the first step and now dummies only fumble with their chips once.

We had a thread about this fairly recently.

I think the rules in most US rooms will allow you to come out with a stack of chips and only bet the portion you want and then bring the rest back to your stack the same way you describe. TDA does not have a rule requiring you to bet everything you bring out into the betting area either.

I'm chasing Suit around the site today ...

It's pretty common to 'cut and paste' a bet in a cash game but I would be much more cautious about it in a tournament setting. TDA doesn't directly address that type of betting motion so you will need to confirm things with the venue/tournament.

I recently saw a tournament stream in Europe where a BB was going to raise. Spent a bunch of time carefully stacking the chips for the bet and then silently pushed them out and then took back his BB. NOPE, Dealer made him leave the BB out there because he didn't pull it back first. GL

Vee Quiva in (near?) Phoenix, in their tournaments, are _very_ strict about chips in front of the cards. If you were to bring out a stack intending to only cut a portion as the bet, without stating the amount first, the whole stack would be considered the bet. They announce this at the beginning of every daily tournament, and the dealers remind players to be careful regarding this rule during the tournament.

Not sure about cash, though.

This is a good example of why we should rename "common sense" to "extremely rare sense".