Sacrificial Dodge

You can defend a friend by throw-
ing yourself into the path of an attack
against him. To do so, you must be
close enough to interpose yourself
between your friend and his attacker
by taking a step (see Step, p. 368).
Announce this after the enemy makes
his attack roll but before your friend
attempts his defense roll.
Use the ordinary rules for a dodge,
except that you cannot combine this
with a retreat (see Retreat, p. 377). If
you succeed, you are hit by the attack.
If you fail, you didn’t move in time,
but your friend still gets his normal
defense roll. In either case, since you
moved, you cannot retreat if you are
attacked before your next turn.