
I've wondered about this one for awhile and finally found a good picture showing it. The unit is at 10 displayed strength, but is giving off 19 rather than 20 supply. This implies both that it has lost .5 hp and that the game tracks 20 actual HP (or 10hp in 0.5 increments). Therefore a 0+ attack isn't predicting 0 damage with a chance of 1, but 0.5 damage.