[pokerswami]

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We do have a half-bet rule. We call it the "50% rule". The important thing to note here is that this will always be overridden by the single oversized chip rule.

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In most cardrooms, the half-bet rule applies only to limit poker, not no-limit poker. While some cardrooms may use the half-bet rule for no-limit, most do not.

This is specifically addressed in Robert's rules of poker:

SECTION 14 - NO LIMIT AND POT-LIMIT

"3. All raises must be equal to or greater than the size of the previous bet or raise on that betting round, except for an all-in wager. Example: Player A bets 100 and player B raises to 200. Player C wishing to raise must raise at least 100 more, making the total bet at least 300. A player who has already acted and is not facing a fullsize wager may not subsequently raise an all-in bet that is less than the minimum bet or less than the full size of the last bet or raise. (The half-the-size rule for reopening the betting is for limit poker only.)

4. Multiple all-in wagers, each of an amount too small to qualify as a raise, still act as a raise and reopen the betting if the resulting wager size to a player qualifies as a raise. Example: Player A bets $100 and Player B raises $100 more, making the total bet $200. If Player C goes all in for less than $300 total (not a full $100 raise), and Player A calls, then Player B has no option to raise again, because he wasn’t fully raised. (Player A could have raised, because Player B raised.)

5. “Completing the bet” is a limit poker wager type only, and not used at big-bet poker.