feedback6 R21A: a 突袭 member may land on a teammate's half when both halves of the field are taken — the two-helper 联防 field and the Final Assault / Hidden Core pair field (the owner's decision of 2026-10-07): Battle.onFieldBoard (onOwnBoard of any player of the battle) read by raidTile only; a lone 联防 helper's empty half, a solo boss field's other half and the hand / 临时整备区 rows stay closed, every other landing rule kept, 乌尔比安's S3 【移动】 keeps onOwnBoard; golden: 8 moved, each parting from the parent at a member's first landing on its teammate's half (checked tick by tick with the parent instrumented) — fields boss-boss_2 / 3 / 4 / 5 / 6-pair and hidden-boss_8 / 10-pair (the right player's 缄默德克萨斯 / 伊内丝 / 仇白 / 耀骑士临光 on the left player's half, 1–7 landings per battle, the first 0.3–39.8 s in), matches coop4-ABYSS-7 (round 6's two-helper 联防: ai_2's 斯卡蒂 on ai_1's half at 52 s; only ai_1 / ai_2 dmgDealt move, 8263 between them); unite-2 unchanged (its two landings stay on their own half)

Tests: test/sim/feedback5-raid-own-board.test.js — the pair field (the right player's member onto the left telin's board tile (2,3), the left player's onto the mirrored right (2,17), the hand rows closed) and the two-helper 联防 (each helper onto the other's half; 乌尔比安 beside a teammate stays on his own) fail on the parent; the solo boss field's hand rows and the lone helper unchanged.
Docs: docs/history/0.2.1.md (new, §26; §26.1 cites the owner's decision and PRTS 卫戍协议/帮助 §联防阶段), the DESIGN index row and versions line, a pointer from §25.18.1, docs/SIM.md (onFieldBoard; onOwnBoard now 乌尔比安's only).

docs/SIM.md

@@ -842,7 +842,8 @@ instance) and skip `'counter'` / `'reflect'` damage. When the guard trips, the l
 | `addLayers(playerId, bondId, n, reason, {source})`, `addCoins(playerId, n)` | layers are a no-op when `flags.layerGainsEnabled` is false (unite/boss); a gain adds at most the room left under `BOND_LAYER_CAP` (999, shared/constants.js `layerGainRoom`: the client's `AddBondCount` min(L + n, 999)) on the live copy — or, without one, on the battle's own gains — and returns what it added (0 at the cap: no hook, no event) |
 | `getPlayer(playerId)` | `{ playerId, seat, side, colOffset, mirror, dir (default unit direction: RIGHT, mirrored side LEFT), facing (its sign), bonds (live copy, layers updated by addLayers), bandId, playerEffects, lpForBoss, dp, units }` |
 | `mapTile(ps, row, col, abs?)` / `mapDir(ps, dir, abs?)` | board → field tile / direction of a player (the FA right-side mirror) |
-| `onOwnBoard(ps, r, c)` | whether a field tile lies on the player's own board — GEO.FIELD (rows 9–12, cols 2–10) mapped onto this field: the 联防 right-hand helper's +8 columns, the boss field's rows 2–5 (never its hand / 临时整备区 rows 0–1), the mirrored right half; the 突袭 landing takes only such tiles (DESIGN §25.18), and so does 乌尔比安's S3 【移动】 (DESIGN §25.17.2) |
+| `onOwnBoard(ps, r, c)` | whether a field tile lies on the player's own board — GEO.FIELD (rows 9–12, cols 2–10) mapped onto this field: the 联防 right-hand helper's +8 columns, the boss field's rows 2–5 (never its hand / 临时整备区 rows 0–1), the mirrored right half; 乌尔比安's S3 【移动】 takes only such tiles (DESIGN §25.17.2) |
+| `onFieldBoard(r, c)` | whether a field tile lies on the board of a player of this field — `onOwnBoard` of any of `players` (the players whose units the battle holds; an eliminated or absent teammate is not one): both halves of the two-helper 联防 field and of a Final Assault / Hidden Core pair field, the own half only for a lone 联防 helper and on a solo boss field, never a boss field's hand / 临时整备区 rows; the 突袭 landing takes only such tiles (DESIGN §25.18, §26.1) |
 | `addDp(playerId, n)`, `retreat(unit, {reason, permanent, dying})`, `relocate(unit, r, c)` | `relocate` only changes the tile (state kept, no event) |
 | `moveRedeploy(unit, r, c, { clearSp })` | a 【移动】 (PRTS 术语释义: "不退场，以当前血量在目标位置部署", a special retreat + redeploy): `relocate`'s checks (false = refused, nothing changed), then a new deployment (`deploySeq` / `aggroSeq` / `deployedAt`) and `deploy {initial:false, move:true}` (deploy effects fire again); no `die` / `death`, timer or cost (不屈 / 阿戈尔's revive never see it); HP, buffs and a running skill are kept (owner's deviation, DESIGN §22.3); `clearSp` empties the SP before the deploy handlers run — 乌尔比安 S3's move (kits/ops/chess_char_5_05-ulpia.js) and 【返回】 (`clearSp`; also the 从不混淆的方向 fallback, content/tokens.js) |
 | `redeploy(unit, { free=true, tile, keepSp })` | immediate (re)deployment of a dead/retreated ally (full HP, `deploy {initial:false}`); `free: false` pays `base.cost` DP (refused without it); without `tile` it lands on the unit's rest tile (`restTile`: where a knocked-out operator lies, else home); `tile: [r, c]` lands on that tile once (home unchanged; refused when off-rect, occupied or a knocked-out operator's tile, no fallback); `keepSp` keeps SP/charges (保留技力), restored before `deploy` fires — 突袭 raids, 阿戈尔 / 不屈 revives where the unit lies |