diff --git a/docs/architecture/legacy-engine-constants.md b/docs/architecture/legacy-engine-constants.md
index 5f3644d..55cb03b 100644
--- a/docs/architecture/legacy-engine-constants.md
+++ b/docs/architecture/legacy-engine-constants.md
@@ -51,6 +51,8 @@ Unit availability is controlled by `GameUnitConstraint` implementations:
 
 - `ReqTech`, `ReqCities`, `ReqRegions`, `ReqMinRelYear`, `Impossible`, etc.
 - Each constraint exposes `test(...)` and `getInfo()` for UI display.
+- `ReqNationAux` gates unit availability by `nation.aux` flags (e.g. research
+  unlocks like `can_화시병사용`), which are written by nation commands.
 
 ## Open Questions / Follow-ups
 
diff --git a/docs/architecture/legacy-engine-constraints.md b/docs/architecture/legacy-engine-constraints.md
index 418253f..2bc4441 100644
--- a/docs/architecture/legacy-engine-constraints.md
+++ b/docs/architecture/legacy-engine-constraints.md
@@ -27,6 +27,10 @@ Constraints declare required inputs using bit flags:
 `Constraint::checkInputValues()` enforces these expectations and throws if
 inputs are missing or malformed.
 
+Some constraints expect `general.aux` to be preloaded as `auxVar`. Command
+evaluation calls `General::unpackAux()` before constraint checks to satisfy
+these requirements.
+
 ## Constraint Helper DSL
 
 `ConstraintHelper` provides factory-style helpers used in command definitions:
diff --git a/docs/architecture/legacy-engine-execution.md b/docs/architecture/legacy-engine-execution.md
index 4102323..ccaff7e 100644
--- a/docs/architecture/legacy-engine-execution.md
+++ b/docs/architecture/legacy-engine-execution.md
@@ -76,8 +76,12 @@ For each general with `turntime < targetDate` (ordered by `turntime, no`):
    - Updates `killturn` based on NPC status, autorun, or `휴식`.
 8. **Queue maintenance & turntime**
    - `pullNationCommand()` / `pullGeneralCommand()` advance queues.
-   - `updateTurnTime()` handles deletion/retirement and sets next `turntime`.
-   - Persist via `General::applyDB()`.
+    - `updateTurnTime()` handles deletion/retirement and sets next `turntime`.
+    - Persist via `General::applyDB()`.
+9. **LastTurn persistence**
+   - General `LastTurn` lives in `general.last_turn` JSON.
+   - Nation `LastTurn` is stored in `nation_env` under `turn_last_{officer_level}`.
+   - `LastTurn.term` only advances when the same command + arg repeats across turns.
 
 ## Command Semantics (BaseCommand)
 
@@ -100,6 +104,16 @@ For each general with `turntime < targetDate` (ordered by `turntime, no`):
 - **Scheduling**: next `turntime` is `addTurn(current, turnterm)` with
   optional `nextTurnTimeBase` override (aux var).
 
+## killturn, block, autorun
+
+- `killturn` acts as an inactivity counter; it is reset to `game_env.killturn`
+  when a non-rest player action completes, and decremented for NPCs, autorun,
+  rest commands, or block states.
+- `block >= 2` forces `killturn` decrement and logs a block message.
+- When `killturn <= 0`, the general is converted to NPC (owner removed) or
+  deleted depending on NPC type and `deadyear`.
+- `autorun_limit` is stored in general `aux` and used to decide AI takeover.
+
 ## Deterministic RNG Seeds
 
 RNG uses `LiteHashDRBG` with `UniqueConst::$hiddenSeed`:
diff --git a/docs/architecture/legacy-engine-general.md b/docs/architecture/legacy-engine-general.md
index 18b3731..1ed115c 100644
--- a/docs/architecture/legacy-engine-general.md
+++ b/docs/architecture/legacy-engine-general.md
@@ -9,6 +9,7 @@ exposes trigger hooks. The main reference is `legacy/hwe/sammo/General.php`.
 - `last_turn` is parsed into `LastTurn`, and a separate `resultTurn` is
   maintained for updates.
 - `penalty` JSON is decoded into `PenaltyKey -> value` map.
+- `aux` JSON is lazily decoded and only written when aux values change.
 - Rank data is tracked with:
   - `rankVarRead` (current read view)
   - `rankVarIncrease` (increment queue)
@@ -53,6 +54,16 @@ Convenience wrappers:
   `BaseCommand::addTermStack()` to advance multi-turn commands.
 - `applyDB()` persists updated fields and writes `last_turn` if it changed.
 
+## Aux and Penalty Behavior
+
+- `aux` is loaded on demand (`unpackAux()`), and `setAuxVar()` writes through to
+  `general.aux` only when values changed.
+- Setting an aux value to `null` deletes the key from JSON.
+- Command constraints that require aux values trigger `General::unpackAux()`
+  before evaluation.
+- `penalty` is used in both `General` logic (AI and permission checks) and
+  API flows (messages, nation tools); runtime expiration is not automatic.
+
 ## Trigger and Modifier Hooks
 
 `General` delegates calculations and trigger lists through action objects: