I had some questions from a couple folks on the Reaper message board who I convinced (after years of propaganda, wait no- pimping, wait no...) to try out Defiance.

One of the questions was this: Is unit perimeter a convex hull?

http://en.wikipedia.org/wiki/Convex_hull

Or alternatively, are two units respecting each other's perimeter if it is possible to draw any unit perimeter at all that does not cross?

If unit perimeter IS a convex hull, as apparently depicted in illustration "Unit Perimeter" DVG p13, then the initial unit perimeter depicted in illustration "Unit Splitting" DVG p15 is incorrect, as counting anti-clockwise from top centre, the unit perimeter should go directly from spondy 5 to boxy 2, rather than through spondy 6 to boxy 1 then boxy 2. Spondy 6 and boxy 1 should then be inside the perimeter and not touching it.

Either way, the illustration on page 13 is slightly ambiguous, but especially so if the perimeter is NOT a convex hull.