Taken from the "help weapon paths" file:
Taking each tert gives access to the tert that follows it in the
same path. Additionally, it also opens access to the next tert in
two "adjacent" paths (see diagram below). For example, taking
Warlord Private (axe one) gives access to Warlord Sergeant (axe
two), but it also gives access to Retiarii Tesserarius (net two)
and Brute Squad Sergeant (bludgeon two).
The following chart shows how the different weapon types relate
to one another. Each path allows players to "sidestep" into an
adjacent path, following either clockwise or counter-clockwise
on the circle:
The same level of tert can be taken from multiple paths, but
tert levels cannot be skipped. Thus the sixth tert of any path,
for example, cannot be taken until the player has first taken
the fifth tert of either that path or an adjacent path.
