This article is from the Fencing FAQ, by Morgan Burke with numerous contributions by others.
According to Article t.10 of the FIE Rules of Competition, the
in-line position is that "in which [the fencer's] sword arm is
straight and the point of his weapon threatens his opponent's
Properly done, the arm should be extended as straight as
possible, and form a more or less continuous line with the blade,
with the point aimed directly at the high lines of the target.
Excessive angulation at the wrist or fingers negates the
point-in-line. Superfluous movement of the point also risks
negating the line, especially in sabre. Derobements/trompements,
however, are permitted.
In foil and sabre, the point-in-line has priority over attacks
that are made without first taking the blade. With these weapons
(but not with epee) it is forbidden to assume the point-in-line
position before the command to fence has been given. In sabre, a
point-in-line that hits with the edge is passe'; if a touch is
registered with the edge, it is properly analyzed as a remise or
counter-attack, except in the case of a derobement.
There are wildly differing opinions on the role of the feet in
the point-in-line. Some claim that any movement forward or
backward invalidates the point-in-line, while others claim that
only forward movement obviates the line. These interpretations
are incorrect, although they may still constitute good advice if
you want to make the point-in-line more obvious to a referee. It
was widely held to be an official ruling that steps or jumps
forward or backward maintained the point-in-line, but lunges or
fleches obviated it. This ruling, apparently based on a
directive from the FIE, was official policy in the USFA for a
while. However, the rulebook does not proscribe any footwork
movements at all, and other FIE rulings hold that footwork, even
a lunge or fleche, has absolutely no effect on the priority of