Penalties in fencing may be of four types: the loss of ground on the piste; the refusal of the president to award a hit which was made; the award of a hit which was not received; or the presentation of a penalty card, which is yellow, red or black.
Loss of ground: A fencer who crosses the side of the piste is penalised by the loss of one metre, and the rule pertaining to this has changed recently. Now, the fencer who crosses the side of the piste is taken back one metre from the point where they began the action which crossed the side (generally from where they are, unless the action was an attack, in which case they would go from where the attack began). If this loss of ground puts the fencer on guard with both feet over the back line, then they have lost the point.
Refusal to award a hit which was made: The president may refuse to award a hit which was made if it was made by an illegal action, or after the command "Halt" or for other reasons described in the rules.
Award of a hit which was not received: A fencer may have a hit awarded against them when they were not, in fact, touched if they crossed the rear of the piste with both feet, or substituted non-valid target for valid, or used the non-sword arm while fencing, or for a variety of other reasons.
Yellow Card: This is a warning and gives no material advantage to the opponent. It is awarded for the first offence from the "first group" (offences are listed in the rules under four groups of increasing gravity). The second offence during that bout, either the same or another from the first group, is penalised with a red card. A fencer cannot receive a yellow card if they have previously received a red card in the same bout. However the yellow cards only last for the duration of the bout.
Red Card: This is awarded for the second and subsequent offences from the first group, or the first and subsequent offences from the second group, or the first offence from the third group (there are some exceptions to this). The red card awards a point to the opponent, and each subsequent red card awards another point. In addition, the fencer at fault may have any hit they made annulled while an opponent's hit may be awarded, in addition to the point given by the card.
Black Card: This card is awarded for the second and subsequent offences in the third group (with some exceptions) and the first offence in the fourth group. The black card indicates expulsion from the tournament, and normally implies that the fencer may not compete again for a certain period (in Australia, they may not compete in the next competition of the same level for which they are eligible). Black cards also remove the fencer's results: they are removed from the ranking list, all other competitors are moved up one place and no ranking points are gained. In certain cases, a black card may indicate expulsion from the venue and may be applied to spectators.