Logic wins
http://www.worldsnooker.com/page/RulesofSnooker
12. Penalties
All fouls will incur a penalty of four points unless a higher one is indicated in paragraph (a) to (d) below. Penalties are:
(a) value of the ball on by
(i) striking the cue-ball more than once,
(ii) striking when both feet are off the floor,
(iii) playing out of turn,
(iv) playing improperly from in-hand, including at the opening stroke,
(v) causing the cue-ball to miss all object balls,
(vi) causing the cue-ball to enter a pocket,
(vii) playing a snooker behind a free ball,
(viii) playing a jump shot,
(ix) playing with a non-standard cue, or
(x) conferring with a partner contrary to Section 3 Rule 17(e).
(b) value of the ball on or ball concerned, whichever is higher, by
(i) striking when any ball is not at rest,
(ii) striking before the referee has completed the spotting of a colour,
(iii) causing a ball not on to enter a pocket,
(iv) causing the cue-ball to first hit a ball not on,
(v) making a push stroke
(vi) touching a ball in play, other than the cue-ball with the tip of the cue as a stroke is made, or
(vii) causing a ball to be forced off the table.
(c) value of the ball on or higher value of the two balls concerned by causing the cue-ball to first hit simultaneously two balls, other than two Reds or a free ball and a ball on.
(d) A penalty of seven points is incurred if the striker
(i) uses a ball off the table for any purpose,
(ii) uses any object to measure gaps or distance,
(iii) plays at Reds, or a free ball followed by a Red, in successive strokes,
(iv) uses any ball other than White as the cue-ball for any stroke once the frame has started,
(v) fails to declare which ball he is on when requested to do so by the referee, or
(vi) after potting a Red or free ball nominated as a Red, commits a foul before nominating a colour.