The use of the non-sword hand and arm to carry out an offensive or defensive action is forbidden (cf. t.114, t.116, t.120 Offences and Penalties). Should such an offence occur, the hit scored by the fencer at fault is annulled.

At foil and sabre, it is forbidden to protect the target area or to substitute another part of the body for the target area, either by covering or by an abnormal movement (cf. t.114, t.116, t.120 Offences and Penalties).

During the fight, the fencer must not, under any circumstances, take hold of any part of the electrical equipment with their non-sword hand (cf. t.114, t.116, t.120 Offences and Penalties).

If during a bout the Referee notices that one of the fencers is making use of their non-sword arm and/or hand, or is protecting or covering the valid target with a non-valid surface, the Refereee can call for the help of two neutral judges who will be designated by the Directoire Technique. The judges, one each side of the piste, will watch one fencer each and will indicate, by raising their hand or when asked by the Referee, if the non-sword arm or hand has been used, or if the fencer has protected or covered the valid target with a non-valid surface (cf. t.49 Extension of the Valid Target, t.114, t.116, t.120 Offences and Penalties).

The Referee may also make the fencers change places so that the fencer committing this fault does not have their back to the Referee.