Syplheed-Reborn/docs/re/mission-objective-vocabulary.md

What the missions actually test — all 28 scripts surveyed

Status: ✅ corpus-wide counts, verified independently; ✅ two idioms identified that change how the numbers read; 🟡 one built-in's semantics only partly read.

All 28 Stage\StageNN.ssb scripts decoded with tools/re-capture/isl.py: 2,085,628 bytes, 25,705 built-in call sites, 108 of the 147 built-ins ever used. Nothing failed to parse. Re-checked here against the survey: 33=0, 34=0, 108 distinct, hp_pct_test 1955, unit_state 1271 — all exact.

✅ The kill-counter primitives are DEAD, game-wide

global_counter0 / global_counter1 (built-ins 33/34) have zero call sites in all 28 stages. Their handlers exist and are wired — they read [0x828F35C4]+8 and +12 into the int result register — and no mission ever calls them.

That settles the "does a wave start after N kills?" question far beyond Stage 02: no mission in the game counts kills. 39 built-ins are never called at all, including timer_start, deploy_and_wait, camera_at, play_voice and screen_fade.

✅ hp_pct_test(unit, 0.0) is a destruction test

1786 of 1955 hp_pct_test calls (91 %) pass threshold 0.0 — 107 of Stage 02's 109 resolvable sites. Built-in 20's handler (0x8226AB78) explains it: above zero it returns pct ≤ threshold, but at exactly 0.0 it takes a separate path that also requires the unit's state field [unit+16] == 4.

So unit_state and hp_pct_test(…, 0) are interchangeable "is it destroyed" tests, and stages simply pick an idiom. Real damage thresholds are the minority: 50 (57×), 30 (19×), 70 (18×), 40 (14×), then a thin tail.

This matters for reading the counts: a stage with no unit_state is not necessarily testing something different — S14 has none, and 25 of its 34 hp_pct_test calls pass 0.0.

✅ squad_survival_pct is a boolean, not a percentage

29 sites, in S06/S07/S08/S09/S15, and every one passes a friendly TCAF squadron and the threshold 99.9. The handler divides current by initial member count with an integer divwu before multiplying by 100.0, so the value can only be 100 or 0.

At a 99.9 threshold that makes every site the predicate "has this friendly squadron lost anybody at all?" — an escort-casualty test. The game has no "destroy N% of a squadron" objective.

✅ The condition vocabulary, and the outliers

pattern	stages
unit_state + hp_pct_test + dist_lt + unit_relation	the story stages
squad_survival_pct (escort intact?)	S06, S07, S08, S09, S15
group_ratio_pct	S01 only, 13 sites, always (TCN001, <ADAN squadron>)
player gauges 132/133/134	S16 only — 11 + 2 + 2 sites
is_engaged	S05 only, 3 sites, all on TCN004

S18–S23, the tutorials, are the outliers by a distance. No flag/trigger machinery at all — zero read_freg, clear_flag, push_trigger, named_event, MARK_LAST_PHASE, FORCE_END_PHASE, and none of the timer family. One set_flag and one END_PHASE each. They are linear scripted lessons, not missions.

S16 has no unit predicates whatsoever — its symbol table 2 holds three entries, and its conditions are a descending player-gauge ladder (75/50/25/10/0). A player-state set piece.

🟡 Not settled

• group_ratio_pct (72) takes two unit indices — blob+4 and blob+12 — and its numerator comes from a pair-keyed lookup through [phase+328] that was not read to the bottom. The natural reading (a per-squadron ratio credited to the player's flight) fits S01's usage, but is not established, so it is not being called "percent killed by the player".
• isl.py's UNIT_ARG omitted 71 and 72, so their second unit operand printed as a bare integer. Noted in the tool; 56 may be the same shape, unverified.
• The timer names in isl.BUILTIN look mismatched: 73 timer_start has zero sites while 123/124 carry the traffic, and their handlers are the run/stop pair. Flagged, not renamed.