Section 4: Players & Officials
The Striker and Turn (Section 2, Rule 5). The player about to play, or in the act of playing, is the "striker," and it remains their turn until a stroke is played without scoring, a foul is committed and all balls have come to rest, the opponent is asked to play again following a foul, the frame is claimed, or the final Black is potted and the cue-ball comes to rest.
Unsporting Conduct (Section 4, Rule 1). A referee will Warn a player for offensive language or gestures, wilfully or persistently unsporting conduct, any other conduct the referee considers amounts to Unsporting Conduct, or a refusal to continue the current frame. If the player commits further Unsporting Conduct after being Warned, the referee shall award the frame to their opponent; a further instance after a frame has already been awarded results in the game being awarded to the opponent. Where conduct is, in the referee's opinion, sufficiently serious, the referee may award the frame or game to the opponent even without a prior Warning having been issued. Any such decision by the referee is final and is not subject to appeal.
Four-handed Snooker (Section 3, Rule 18). In a four-handed game, each side of two players alternates frames, with each side's internal order of play determined — and, once set, maintained — at the start of each frame. Partners may confer during a frame but not while one of them is the striker and has approached the table until their turn has ended; if a striker's partner commits an infringement, the striker is treated as the offender.
Officials. Section 5 of the Rules establishes the officiating roles of the Referee, the Marker, and the Stroke Recorder, together with provisions for Assistance by Officials. Consistent with the striker/officiating duties evidenced throughout Sections 2 and 3, the referee is the sole judge of fact during play: the referee calls FOUL and TOUCHING BALL, determines whether the cue-ball is snookered, adjudicates whether a stroke constitutes a Miss, oversees the correct spotting of colours, and rules on the value and application of penalty points. Where no referee is present, Section 3, Rule 21(b) provides that the opposing player or side is regarded as fulfilling that role for the purposes of the Rules.