Underbluffing is the opposite error from overbluffing: the player does not include sufficient bluffs in their betting range, making it excessively value-heavy. When detected, the opponent can fold all non-premium hands with impunity, as bets nearly always represent genuine value. Underbluffing is frequently caused by loss aversion, fear of getting called while bluffing, or failure to identify strong bluff candidates. The theoretical consequence is leaving EV on the table by not maximizing fold equity in spots where bluffs would be profitable.