The battle engine diverged from the documented combat model
(game/rules.txt "Сражения") in three ways:
- the destruction roll was inverted (rand >= p), so a near-certain hit
destroyed its target only ~(1-p) of the time;
- a whole group fired as a single ship (Armament shots per round)
regardless of its ship count, so fleet size never affected offence;
- the defending mass used the whole group's full mass instead of one
target ship's, weakening grouped ships' shields by ~Number^(1/3).
SingleBattle now resolves ship by ship: every living ship fires once per
round in random order across all groups, each gun targets a random enemy
ship (weighted by group size), and the destruction roll matches the
documented probability. FilterBattleOpponents evaluates per-ship mass.
Also fixes opponent-map initialisation in ProduceBattles that kept only
an attacker's last opponent.
The rules already describe this model, so no documentation change is
needed. Tests: per-ship one-sided wipe, destruction-roll direction, and
the updated per-ship-mass probability expectation.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Legacy reports list the same `(race, className)` pair across several
roster rows; the engine likewise creates one ShipGroup per arrival.
Both the legacy parser and `TransformBattle` were keyed on shipClass
without summing — only the last row / group's counts survived, so a
protocol's destroy count appeared to exceed the recorded initial
roster. The UI worked around this with phantom-frame logic.
Both parser and engine now SUM `Number`/`NumberLeft` across rows /
groups sharing the same class; the phantom-frame workaround is gone.
KNNTS041 turn 41 planet #7 reconciles: `Nails:pup` 1168 initial −
86 survivors = 1082 destroys.
The engine's previously latent nil-map write on `bg.Tech` (would
have paniced on any group with non-empty Tech) is fixed in the same
patch — it blocked the aggregation regression test.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Ilia Denisov