[ETA: damn my slow fingers!]
Here are the relevant rules as I see them:
RRoP
Quote:
SECTION 3 - GENERAL POKER RULES
13. A player who bets or calls by releasing chips into the pot is bound by that action and must make the amount of the wager correct. (This also applies right before the showdown when putting chips into the pot causes the opponent to show the winning hand before the full amount needed to call has been put into the pot.) However, if you are unaware that the pot has been raised, you may withdraw that money and reconsider your action, provided that no one else has acted after you. At pot-limit or no-limit betting, if there is a gross misunderstanding concerning the amount of the wager, see Section 14, Rule 8.
Quote:
SECTION 14 - NO LIMIT AND POT-LIMIT
8. If there is a discrepancy between a player's verbal statement and the amount put into the pot, the bet will be corrected to the verbal statement.
12. Because the amount of a wager at big-bet poker has such a wide range, a player who has taken action based on a gross misunderstanding of the amount wagered may receive some protection by the decision-maker. A "call" or “raise” may be ruled not binding if it is obvious that the player grossly misunderstood the amount wagered, provided no damage has been caused by that action. Example: Player A bets $300, player B reraises to $1200, and Player C puts $300 into the pot and says, “call.” It is obvious that player C believes the bet to be only $300 and he should be allowed to withdraw his $300 and reconsider his wager. A bettor should not show down a hand until the amount put into the pot for a call seems reasonably correct, or it is obvious that the caller understands the amount wagered. The decision-maker is allowed considerable discretion in ruling on this type of situation. A possible rule-of-thumb is to disallow any claim of not understanding the amount wagered if the caller has put eighty percent or more of that amount into the pot.
Example: On the end, a player puts a $500 chip into the pot and says softly, “Four hundred.” The opponent puts a $100 chip into the pot and says, “Call.” The bettor immediately shows the hand. The dealer says, “He bet four hundred.” The caller says, “Oh, I thought he bet a hundred.” In this case, the recommended ruling normally is that the bettor had an obligation to not show the hand when the amount put into the pot was obviously short, and the “call” can be retracted. Note that the character of each player can be a factor. (Unfortunately, situations can arise at big-bet poker that are not so clear-cut as this.)
Rule 3.13 refers to 14.8, which seems to clearly be a reference error. I believe it intends to refer to 14.12.
The only reference to forcing undercalls up to be full calls seems to be 3.13. Having said that, 3.13 also contains two exceptions in its own text (missing a raise before action behind, and gross misunderstandings).
Having said THAT, in at least one of the examples listed above, there was action behind the undercall (a fold by the original bettor). So I'm not sure this rule makes it very clear, other than to say that the decision maker has considerable latitude to decide how to rule.
I don't think it is at all clear or fair to say that all undercalls must be brought up to full calls by rule, though that may be the ruling in many/most cases.
For clarity, the TDA rule is perhaps a little more clear cut, but still gives the TD significant leeway:
Quote:
B: A player undercalls by declaring or pushing out less than the call amount without first declaring “call”. An undercall is a mandatory full call if made in turn facing 1) any bet heads-up or 2) the opening bet on any round multi-way. In other situations, TD’s discretion applies. The opening bet is the first chip bet of each betting round (not a check). In blind games the posted BB is the pre-flop opener. All-in buttons reduce undercall frequency (See Recommended Procedure 1). This rule governs when players must make a full call and when, at TDs discretion they may forfeit an undercall and fold. For underbets and underraises, see Rule 43.
C: If two or more undercalls occur in sequence, play backs up to the first undercaller who must correct his or her bet per Rule 42-B. The TD will determine how to treat hands of the remaining bettors based on the circumstances.
Quote:
Rule 42: Binding Declarations / Undercalls in Turn
Example 1: NLHE, blinds 1000-2000. Post-flop, A opens for 2000, B raises to 8000, C pushes out 2000 silently. C has undercalled B’s bet. Per Rule 42-B, because B is not the opener (A is) and the round is still multi-way, at TD’s discretion C may be required to make a full call or allowed to forfeit the 2000 undercall and fold.
Example 2: NLHE, blinds 1000-2000. Post-flop 4 players remain. A opens for 8000, B silently puts out 2000. Per Rule 42-B, B undercalled the opening bet and must make a full call of 8000.
Example 3: NLHE, blinds 1000-2000. Post-flop, A opens for 2000, B raises to 8000, C declares “call”. Per Rule 42-A, C has made a general verbal declaration (“call”) in turn. C is obligated to call B’s full bet of 8000.
The primary difference seems to be that:
(1) undercalls are forfeited if the player is allowed to fold, rather than allowing the player to take the bet back and reconsider
(2) verbal "calls" are binding even if there is a missed raise, only chip bets are potentially allowed to not complete the full call.