For purposes of fairness, guess-fingers has a few basic no-no's, punishable by stiff fines (deep quaffs), such as trying to change the throw halfway through or failing to call a number.
例如：講求出拳乾淨俐落的「拳不離母」，是為了防止有人中途換拳；「啞巴不成拳」則規定只出拳不喊話，無效。