1.13 What constitutes an attack?
 
     According to Article 10 of the FIE rules of competition, "the 
     attack is the initial offensive action made by extending the arm 
     and continuously threatening the valid target of the opponent."
 
     A threatening weapon is normally interpreted to be one that will 
     hit the opponent if nothing is done to prevent it.  In other 
     words, a weapon threatens if it is moving towards the target in a 
     smooth, unbroken trajectory.  This trajectory can be curved, 
     especially if the attack is indirect, compound, or involves a 
     cutting action.  Hesitations and movements of the blade away from 
     the target will usually be perceived as a break in the attack or a
     preparation of the attack.
 
     One common misconception is that a straight or straightening arm is
     required to assert the attack.  While this was a traditional
     interpretation of the above rule, both the strict wording and
     prevailing modern interpretation do not require that the attacker's
     arm become straight or even nearly so.  It is sufficient if the arm
     extends, even just slightly, from its normal on-guard position.  A
     long arm is still good style, though, since it gives superior reach
     and clearly shows the fencer's intent.  While the attack can often
     be asserted with only slight extension, retraction of the arm will
     almost always be interpreted as a break in the attack.
 
     Another common misconception is that a point attack does not
     threaten unless the point is in line.  This is not generally true.
     An out-of-line point does threaten if it is moving towards the
     target on a smooth, unbroken trajectory.  The most common example
     of this is the coupe' (cut-over), in which the blade is pulled out
     of line to avoid the the opponent's blade, and then returned into
     line to finish the attack.  Coupe' takes the right-of-way
     immediately, even though the point is initially pulled out of
     line.  So-called "flicks", relatives of the coupe' that involve
     whipping the foible of the blade around parries or blocking body
     parts, can also take the right-of-way when the blade starts its
     final forward stroke.
 
     Many fencers are under the mistaken impression that a bent arm or
     out-of-line point constitutes a preparation, and therefore that
     they can rightfully attack into it.  If the bent arm is extending
     and the out-of-line point is moving towards the target, however,
     this assumption is usually false under modern fencing conventions.
     A successful attack on the preparation must clearly precede the
     opponent's initiation of the phrase or a break in his attack, or
     else arrive a fencing time ahead of his touch.

     Sabre fencers must also consider Article 417 of the Rules of
     Competition, which states when the attack must land relative to the
     footfalls of a lunge, advance-lunge, (and fleche, historically).
     Attacks that arrive after the prescribed footfall are deemed
     continuations, and do not have right-of-way over the
     counter-attack.  Sabre fencers must also remember that whip-over
     touches can sometimes be interpreted as remises, and not
     mal-parries.