Operator ruling (2026-09-25): "proportional absorption; go". A multi-cell item
struck by several lanes of one shot now absorbs their combined incoming damage
(up to its own remaining durability) and each lane's leftover is in proportion
to what it brought, replacing the old behaviour where whichever lane Apply
happened to visit first drained the item and the next lane inherited whatever
was left.
Entity.Absorb is split into ArmorAbsorb (per-cell, never shared) and ItemAbsorb
(the single-lane path), so FireControl.Apply can call armour immediately and
defer item resolution only for a cell whose item is reachable by more than one
lane this shot. FireControl.Apply gains a geometric survey (which items are
reachable by >1 lane, decided before any damage is applied) and takes the
untouched sequential walk (ApplySequential) whenever nothing is shared, or a
new coordinated walk (ApplyWithSharedItems) that deposits each lane's
post-armour remainder into a shared item's pool and resolves it once every
contributing lane has arrived, splitting the leftover proportionally
(sum-then-split, order-independent by construction). A deterministic tie-break
(smallest first-contact Entry) breaks the rare "opposite order" deadlock two
non-convex shared items can create between two lanes.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>