diff --git a/docs/architecture/legacy-engine-auction.md b/docs/architecture/legacy-engine-auction.md
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+# Legacy Auctions and Betting
+
+This document covers the auction and betting systems: how auctions open/close,
+what resources they trade, and how betting payouts are calculated. References
+include `legacy/hwe/sammo/Auction*.php`, `legacy/hwe/func_auction.php`, and
+`legacy/hwe/sammo/Betting.php`.
+
+## Auction Types and Entry Points
+
+- `Auction` (base class): shared bid logic and close-date extensions.
+- `AuctionBuyRice`: sell rice for gold.
+- `AuctionSellRice`: sell gold for rice.
+- `AuctionUniqueItem`: bids use inheritance points for unique items.
+- `processAuction()` in `legacy/hwe/func_auction.php` closes finished auctions.
+- `registerAuction()` creates neutral (NPC-hosted) buy/sell auctions.
+
+## Auction Data Model
+
+Primary tables:
+
+- `ng_auction`: auction metadata (type, target, host, close date, detail).
+- `ng_auction_bid`: per-bid rows for each auction.
+
+The `AuctionInfo` and `AuctionInfoDetail` DTOs are serialized into
+`ng_auction` columns for structured access.
+
+## Core Auction Flow
+
+1. **Open**
+   - `AuctionBasicResource::openResourceAuction()` validates amounts and
+     host resources, then inserts `ng_auction`.
+   - `AuctionUniqueItem::openItemAuction()` checks availability, reserves
+     unique items, and posts a global history notice.
+2. **Bid**
+   - Bids are inserted into `ng_auction_bid` and can extend the close date.
+   - Reverse auctions (when `detail->isReverse`) sort by lowest bid.
+3. **Close** (`tryFinish()` from the concrete auction)
+   - If no bids: `rollbackAuction()` returns resources to host and logs.
+   - With bids: `finishAuction()` transfers resources, logs, and sends messages.
+4. **Processing**
+   - `processAuction()` scans auctions past `close_date` and finishes them.
+
+## Unique Item Auctions
+
+- Currency: inheritance points (`ResourceType::inheritancePoint`).
+- Host identity is obfuscated using `genObfuscatedName()` and a deterministic
+  shuffled name pool stored in `game_env.obfuscatedNamePool`.
+- Limits and availability are enforced against `GameConst::$allItems` and
+  existing ownership in `general` rows.
+
+## Betting System
+
+Betting is an independent KV-backed system:
+
+- `Betting::openBetting()` stores `BettingInfo` in KV storage (`betting`).
+- `Betting::bet()` inserts or updates `ng_betting` rows and charges either
+  gold or inheritance points.
+- `Betting::giveReward()` distributes payouts to winners (exclusive or shared).
+
+Event actions controlling lifecycle:
+
+- `OpenNationBetting`: opens a nation-strength bet and registers a
+  `DESTROY_NATION` event to close it.
+- `FinishNationBetting`: evaluates winners when only N nations remain.
+
+## RNG Notes
+
+- `Auction::genObfuscatedName()` uses `hiddenSeed + 'obfuscatedNamePool'` to
+  shuffle the name pool once and reuse it from `game_env`.
+- `registerAuction()` relies on an injected RNG to randomize neutral auctions.
+
+## Open Questions / Follow-ups
+
+- The exact schedule for `registerAuction()` is outside this file; it is
+  likely called from monthly or timed maintenance.
+- Unique-item auction close-date extension limits depend on
+  `AuctionUniqueItem` constants and `turnterm`; verify scenarios that override
+  auction timing.
diff --git a/docs/architecture/legacy-engine-city.md b/docs/architecture/legacy-engine-city.md
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+# Legacy City Data and Helpers
+
+This document describes how city data is defined and accessed in the legacy
+engine. References include `legacy/hwe/sammo/CityConstBase.php`,
+`legacy/hwe/sammo/CityInitialDetail.php`, and `legacy/hwe/sammo/CityHelper.php`.
+
+## City Constants (CityConst)
+
+`CityConstBase` defines default city data and lookup helpers:
+
+- `CityConstBase::$initCity` includes:
+  - id, name, level, population, agri/comm/secu/def/wall,
+    region, coordinates, and path connections.
+- Region and level maps convert labels to numeric codes.
+- `CityConstBase::byID()` and `byName()` return `CityInitialDetail` objects.
+
+During scenario build, the engine generates `d_setting/CityConst.php` from the
+scenario map file, replacing or extending these defaults.
+
+## CityInitialDetail
+
+`CityInitialDetail` is a plain data object containing the initial
+static attributes for each city:
+
+- `id`, `name`, `level`, `population`
+- `agriculture`, `commerce`, `security`, `defence`, `wall`
+- `region`, `posX`, `posY`, `path` (adjacent city ids)
+
+## CityHelper Cache
+
+`CityHelper` caches live DB city rows for fast lookup:
+
+- `getAllCities()` returns a map keyed by city id.
+- `getAllNationCities($nationID)` returns all cities for a nation.
+- `getCityByName()` resolves a name to a DB row (with a warning if missing).
+
+Cache invalidation is manual via `CityHelper::flushCache()`.
+
+## Path Connectivity
+
+City connectivity (used for supply and movement) is defined by the
+`path` list in `CityConst` and referenced by systems like
+`UpdateCitySupply` to traverse same-nation city graphs.
+
+## Open Questions / Follow-ups
+
+- Scenario-specific map files (`legacy/hwe/scenario/map/*.php`) override city
+  data; document per-map deltas when needed.
diff --git a/docs/architecture/legacy-engine-constants.md b/docs/architecture/legacy-engine-constants.md
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+# Legacy Game Constants and Unit Sets
+
+This document summarizes the static configuration layers that define game
+rules and unit sets. References include `legacy/hwe/sammo/GameConstBase.php`,
+`legacy/hwe/sammo/GameUnitConstBase.php`, `legacy/hwe/sammo/GameUnitDetail.php`,
+and `legacy/hwe/sammo/GameUnitConstraint/*`.
+
+## GameConst (Rules)
+
+`GameConstBase` defines the default rule set:
+
+- Turn limits, stat caps, and progression thresholds.
+- Resource floors (`basegold`, `baserice`) and maintenance coefficients.
+- Command lists (`availableGeneralCommand`, `availableChiefCommand`).
+- Availability lists for specials, items, and nation types.
+- Scenario overrides apply via `Scenario::buildConf()`.
+
+During scenario build, the engine generates `d_setting/GameConst.php` from
+`GameConstBase` and scenario overrides (see
+`docs/architecture/legacy-scenarios.md`).
+
+## Unit Sets (GameUnitConst)
+
+`GameUnitConstBase` defines the base unit list and their combat properties:
+
+- Unit identifiers, arm types, and labels.
+- Base attack/defence stats, speed, avoid, magic coefficients.
+- Cost and rice consumption.
+- Attack/defence coefficients vs. other arm types.
+- Attached trigger lists (`initSkillTrigger`, `phaseSkillTrigger`).
+- Requirements via `GameUnitConstraint` objects.
+
+Scenario build emits `d_setting/GameUnitConst.php` based on the selected
+`unitSet` (`scenario/unit/*.php`).
+
+## GameUnitDetail
+
+`GameUnitDetail` is the runtime representation of a crew type:
+
+- Computes derived attack/defence using general stats and tech (`getTechAbil`).
+- Calculates resource costs (`costWithTech`, `riceWithTech`).
+- Applies attack/defence multipliers by opponent crew type.
+- Can include an `iActionList` (crew-type-specific action modules).
+
+Crew types are also `iAction` providers, enabling triggers and stat modifiers
+through `General::getActionList()`.
+
+## Unit Constraints
+
+Unit availability is controlled by `GameUnitConstraint` implementations:
+
+- `ReqTech`, `ReqCities`, `ReqRegions`, `ReqMinRelYear`, `Impossible`, etc.
+- Each constraint exposes `test(...)` and `getInfo()` for UI display.
+
+## Open Questions / Follow-ups
+
+- Scenario-specific overrides may redefine available units or unit sets;
+  document those deltas per scenario when needed.
diff --git a/docs/architecture/legacy-engine-constraints.md b/docs/architecture/legacy-engine-constraints.md
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+# Legacy Constraint System
+
+This document describes the constraint framework used to validate command
+preconditions. References include `legacy/hwe/sammo/Constraint/Constraint.php`
+and `legacy/hwe/sammo/Constraint/ConstraintHelper.php`.
+
+## Core Concepts
+
+Constraints are reusable predicate classes that validate a command’s inputs and
+state. They are built per-command and executed in order:
+
+- Each constraint extends `Constraint` and implements `test()`.
+- `Constraint::testAll()` iterates a list of constraints and returns the first
+  failure `[constraintName, reason]` or `null` for success.
+- `BaseCommand::hasFullConditionMet()` uses these to decide command validity.
+
+## Required Input Flags
+
+Constraints declare required inputs using bit flags:
+
+- `REQ_GENERAL`, `REQ_CITY`, `REQ_NATION`
+- `REQ_DEST_GENERAL`, `REQ_DEST_CITY`, `REQ_DEST_NATION`
+- `REQ_ARG` with typed sub-flags:
+  - `REQ_STRING_ARG`, `REQ_INT_ARG`, `REQ_NUMERIC_ARG`, `REQ_BOOLEAN_ARG`,
+    `REQ_ARRAY_ARG`, `REQ_BACKED_ENUM_ARG`
+
+`Constraint::checkInputValues()` enforces these expectations and throws if
+inputs are missing or malformed.
+
+## Constraint Helper DSL
+
+`ConstraintHelper` provides factory-style helpers used in command definitions:
+
+- Examples: `AllowWar()`, `NearCity($distance)`, `ReqGeneralGold($amount)`,
+  `NotOccupiedDestCity()`, `AllowDiplomacyStatus(...)`, etc.
+- These helpers return `[ConstraintName, arg]` tuples consumed by
+  `Constraint::testAll()`.
+
+## Common Constraint Classes
+
+Constraints are organized by domain:
+
+- **Diplomacy**: `AllowDiplomacyStatus`, `AllowDiplomacyBetweenStatus`.
+- **Nation/City**: `OccupiedCity`, `NotCapital`, `RemainCityCapacity`.
+- **General**: `ReqGeneralCrew`, `ReqGeneralGold`, `MustBeTroopLeader`.
+- **Routing**: `HasRoute`, `HasRouteWithEnemy`.
+
+Each constraint sets a failure reason string used by UI and logs.
+
+## Open Questions / Follow-ups
+
+- Some constraints rely on `env` values (`turnterm`, `year`, etc.); document
+  each command’s exact `env` payload when porting.
diff --git a/docs/architecture/legacy-engine-diplomacy.md b/docs/architecture/legacy-engine-diplomacy.md
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+# Legacy Diplomacy and Messaging
+
+This document summarizes the legacy message system and how diplomatic messages
+trigger nation command flows. References include
+`legacy/hwe/sammo/Message.php`, `legacy/hwe/sammo/DiplomaticMessage.php`,
+`legacy/hwe/sammo/MessageTarget.php`, and `legacy/hwe/sammo/Target.php`.
+
+## Message Types and Mailboxes
+
+`Message` supports multiple mailbox types:
+
+- **Public**: `MAILBOX_PUBLIC` (global announcements).
+- **National**: `MAILBOX_NATIONAL + nationID` for diplomacy/nation mail.
+- **Private**: mailbox id is the receiver general id.
+
+Message types (`MessageType`) include `public`, `national`, `private`,
+and `diplomacy`.
+
+## Message Lifecycle
+
+- `Message::send()` (not shown here) writes to the `message` table.
+- `Message::getMessagesFromMailBox()` reads by mailbox/type with validity
+  filtering (`valid_until > now`).
+- `Message::buildFromArray()` instantiates:
+  - `DiplomaticMessage` when type is diplomacy.
+  - `ScoutMessage` or `RaiseInvaderMessage` when `option.action` matches.
+
+## DiplomaticMessage Flow
+
+`DiplomaticMessage` wraps diplomacy requests and accepts/rejects them:
+
+- Supported actions:
+  - `TYPE_NO_AGGRESSION` (불가침)
+  - `TYPE_CANCEL_NA` (불가침 파기)
+  - `TYPE_STOP_WAR` (종전)
+- `agreeMessage()` validates:
+  - message is still valid
+  - receiver is a valid diplomacy officer
+- On accept, builds and runs the matching nation command:
+  - `che_불가침수락`, `che_불가침파기수락`, `che_종전수락`
+  - Uses `NoRNG` to avoid randomness in acceptance.
+
+Each acceptance updates `diplomacyDetail` with command briefs and writes logs.
+
+## Message Targets
+
+`MessageTarget` and `Target` provide lightweight identifiers:
+
+- `MessageTarget` includes general/nation names, colors, and icons.
+- Helper constructors (`buildQuick`, `buildFromGeneralObj`) resolve from DB.
+
+## Open Questions / Follow-ups
+
+- The full list of `MessageType` values and message table schema live outside
+  this file and can be documented alongside the UI mailbox APIs.
diff --git a/docs/architecture/legacy-engine-economy.md b/docs/architecture/legacy-engine-economy.md
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+# Legacy Economy and Monthly Updates
+
+This document summarizes the legacy economic pipeline: monthly income,
+maintenance, population growth, city supply recalculation, and nation level
+updates. References include `legacy/hwe/func_time_event.php`,
+`legacy/hwe/sammo/Event/Action/*`, and `legacy/hwe/sammo/TurnExecutionHelper.php`.
+
+## Entry Points
+
+- `TurnExecutionHelper::executeAllCommand()`
+  - Calls `runEventHandler(PRE_MONTH)` → `preUpdateMonthly()` → `turnDate()` →
+    `runEventHandler(MONTH)` → `postUpdateMonthly()`.
+- Event actions under `legacy/hwe/sammo/Event/Action/` execute concrete
+  economic updates.
+
+## Monthly Income (ProcessIncome)
+
+`Event/Action/ProcessIncome` distributes **gold** and **rice** on schedule:
+
+- Collects all nations and cities, groups generals per nation.
+- Computes income using:
+  - `getGoldIncome()` / `getRiceIncome()` from `func_time_event.php`.
+  - `getWallIncome()` for rice from walls (same file).
+- Applies nation tax rate (`rate_tmp`) and salary ratio (`bill`).
+- Pays generals by `dedication` via `getBill()`.
+- Updates `nation_env.prev_income_{gold|rice}` and logs to history.
+
+Key dependencies:
+- `GameConst::$basegold`, `GameConst::$baserice` for minimum reserves.
+- `GameConst::$resourceActionAmountGuide` for action amounts.
+- `iAction::onCalcNationalIncome()` for nation-type modifiers.
+
+## Semiannual Maintenance (ProcessSemiAnnual)
+
+`Event/Action/ProcessSemiAnnual` applies upkeep and growth:
+
+- City stats decay by 1% (agri/comm/secu/def/wall).
+- Population growth via `popIncrease()`:
+  - Uses tax rate (`rate_tmp`) and security.
+  - Nation type can adjust via `onCalcNationalIncome('pop', ...)`.
+- General and nation resources decay (1–5% bands based on thresholds).
+
+## War Income and Casualties (ProcessWarIncome)
+
+`Event/Action/ProcessWarIncome`:
+
+- Converts `city.dead` into national gold income (supply-based war income).
+- Returns 20% of `dead` to population (`pop += dead * 0.2`), then clears `dead`.
+
+## City Supply and Isolation (UpdateCitySupply)
+
+`Event/Action/UpdateCitySupply`:
+
+- BFS from each nation capital through `CityConst` paths to mark `supply = 1`.
+- Unsupplied cities (`supply = 0`) receive 10% stat/pop loss monthly.
+- Generals in unsupplied cities lose 5% crew/train/atmos.
+- Cities with `trust < 30` become neutral (nation = 0), and officers are reset.
+
+## Nation Level Updates (UpdateNationLevel)
+
+`Event/Action/UpdateNationLevel`:
+
+- Nation level increases based on number of level≥4 cities.
+- On level-up:
+  - Grants gold/rice bonus.
+  - Logs global and national history.
+  - Initializes `nation_turn` rows for new chief levels.
+  - Runs a unique-item lottery (deterministic RNG tagged `nationLevelUp`).
+
+## City Trade Rates (RandomizeCityTradeRate)
+
+- Once per month, adjusts `city.trade` with deterministic RNG:
+  - Probability depends on city level.
+  - Trade rate ranges 95–105 when triggered.
+
+## RNG Notes
+
+Economic events using RNG seed with `UniqueConst::$hiddenSeed` and a
+feature-specific tag:
+
+- `RandomizeCityTradeRate`: `hiddenSeed + 'randomizeCityTradeRate' + year + month`
+- `UpdateNationLevel`: `hiddenSeed + 'nationLevelUp' + year + month + nationID`
+
+## Open Questions / Follow-ups
+
+- `preUpdateMonthly()`, `postUpdateMonthly()`, and `turnDate()` live in
+  `legacy/hwe/func_time_event.php` and `legacy/hwe/func.php`; their full
+  side effects should be expanded alongside this document.
diff --git a/docs/architecture/legacy-engine-events.md b/docs/architecture/legacy-engine-events.md
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@@ -0,0 +1,86 @@
+# Legacy Event System
+
+This document summarizes how the legacy event system executes scenario- and
+turn-based events, and how static event hooks are wired into commands. Primary
+references include `legacy/hwe/sammo/TurnExecutionHelper.php`,
+`legacy/hwe/sammo/Event/*`, and `legacy/hwe/sammo/StaticEventHandler.php`.
+
+## Entry Points
+
+- `TurnExecutionHelper::runEventHandler(EventTarget $eventTarget)`
+  - Loads `event` table rows by target and priority, evaluates conditions, and
+    runs actions.
+- `StaticEventHandler::handleEvent(...)`
+  - Invoked by many commands and API handlers to run per-action static hooks.
+
+## Event Table Dispatch
+
+`runEventHandler()` drives the dynamic event pipeline:
+
+1. Query `event` rows with `target = {PRE_MONTH|MONTH|OCCUPY_CITY|DESTROY_NATION|UNITED}`
+   (ordered by `priority DESC, id ASC`).
+2. Decode `condition` and `action` JSON.
+3. Build a `Event\EventHandler` with condition + action lists.
+4. Execute `tryRunEvent($env)` where `$env` is `game_env` KV storage plus
+   `currentEventID`.
+
+Events are used inside the monthly pipeline and in special moments like
+city occupation (`EventTarget::OCCUPY_CITY`, called by some commands).
+
+## Condition and Action DSL
+
+`Event\Condition::build()` and `Event\Action::build()` decode JSON arrays into
+class instances:
+
+- **Condition**
+  - Supports logic combinators (`and`, `or`, `xor`, `not`) via
+    `Event\Condition\Logic`.
+  - Built-in condition types include:
+    - `Date`, `DateRelative`, `Interval`
+    - `RemainNation`
+    - `ConstBool`
+  - Conditions return `{ value, chain }` for tracing.
+
+- **Action**
+  - Actions are classes under `Event/Action/` with `run(array $env)`.
+  - The dispatcher instantiates them from `action` arrays like
+    `['ProcessIncome', 'gold']`.
+
+## Common Event Actions (Examples)
+
+These are the action modules observed in the legacy tree:
+
+- **Economy & upkeep**: `ProcessIncome`, `ProcessSemiAnnual`, `ProcessWarIncome`
+- **World state**: `UpdateCitySupply`, `UpdateNationLevel`, `RandomizeCityTradeRate`
+- **NPC/Invader flow**: `RaiseInvader`, `RaiseNPCNation`, `ProvideNPCTroopLeader`
+- **Betting & unique items**: `OpenNationBetting`, `FinishNationBetting`,
+  `LostUniqueItem`, `MergeInheritPointRank`
+- **Event lifecycle**: `DeleteEvent`, `NoticeToHistoryLog`
+
+All action execution uses the event environment (`year`, `month`, `startyear`,
+`turnterm`, etc.) coming from `game_env`.
+
+## Static Events (Command Hooks)
+
+Static events are hooks triggered directly by commands/APIs:
+
+- `StaticEventHandler::handleEvent()` looks up handler names from
+  `GameConst::$staticEventHandlers[$eventType]`.
+- Handlers live under `legacy/hwe/sammo/StaticEvent/` and implement
+  `BaseStaticEvent::run()`.
+- These hooks are used to extend command behavior without modifying the
+  command code itself (e.g., troop join/exit side effects).
+
+## RNG Notes
+
+Dynamic event actions can use deterministic RNG by constructing
+`LiteHashDRBG` with `UniqueConst::$hiddenSeed` and an event-specific tag.
+Examples include `RandomizeCityTradeRate` and `UpdateNationLevel`.
+
+## Open Questions / Follow-ups
+
+- `Event\Engine` is a stub with a TODO; it is not currently used in the main
+  turn pipeline.
+- The full mapping of `GameConst::$staticEventHandlers` to events should be
+  extracted from scenario configs and command usage when documenting specific
+  rule packs.
diff --git a/docs/architecture/legacy-engine-items.md b/docs/architecture/legacy-engine-items.md
new file mode 100644
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+++ b/docs/architecture/legacy-engine-items.md
@@ -0,0 +1,78 @@
+# Legacy Items, Traits, and Action Modules
+
+This document summarizes the legacy action modules that supply modifiers and
+triggers: items, specials, personalities, nation types, crew types, and
+scenario effects. Primary references include `legacy/hwe/sammo/iAction.php`,
+`legacy/hwe/sammo/BaseItem.php`, `legacy/hwe/sammo/BaseSpecial.php`,
+and `legacy/hwe/sammo/Action*/` directories.
+
+## Core Concept: `iAction`
+
+All traits/items/effects implement `iAction` and are merged by
+`General::getActionList()` (see `docs/architecture/legacy-engine-general.md`).
+They can:
+
+- Modify stats and command calculations (`onCalcStat`, `onCalcDomestic`, etc.).
+- Provide triggers (`getPreTurnExecuteTriggerList`, battle init/phase triggers).
+- Apply ad-hoc effects (`onArbitraryAction`).
+
+`DefaultAction` provides no-op implementations for all hooks.
+
+## Item System
+
+- Base class: `BaseItem` implements `iAction` and exposes:
+  - `getCost()`, `isConsumable()`, `isBuyable()`, `getReqSecu()`.
+- Stat items inherit `BaseStatItem` and apply a fixed stat bonus in
+  `onCalcStat()` based on class name tokens.
+- Item instances live on the general (`General::getItem()`); items can also
+  insert battle triggers (see `ActionItem/`).
+
+Items are configured via `GameConst::$allItems` and scenario overrides.
+
+## Specials (Domestic / War)
+
+- Base class: `BaseSpecial` (implements `iAction`).
+- `ActionSpecialDomestic/*` modifies domestic outcomes
+  (`onCalcDomestic`), e.g., cost/success/score adjustments.
+- `ActionSpecialWar/*` injects battle triggers or stat modifiers.
+- Weighting and eligibility are managed by `SpecialityHelper`:
+  - Uses `selectWeight` + stat/arm constraints to choose specials.
+  - Deterministic RNG affects special selection for NPCs or resets.
+
+## Personalities
+
+- Stored in `ActionPersonality/*` and also implement `iAction`.
+- Typically adjust core stats or apply small domestic bonuses.
+
+## Nation Types
+
+- `ActionNationType/*` extends `BaseNation`.
+- Provide global modifiers to income and domestic outcomes.
+- Injected per-nation via `buildNationTypeClass()`.
+
+## Crew Types (Units as Actions)
+
+- `ActionCrewType/*` defines per-crew `iAction` additions.
+- Crew types can alter battle order, apply triggers, or modify war stats.
+- For example, `che_성벽선제` forces city battle order to a high value.
+
+## Scenario Effects
+
+- `ActionScenarioEffect/*` provides scenario-wide modifiers
+  (e.g., attacker advantage, trigger overrides).
+- Bound to `GameConst::$scenarioEffect` during scenario build.
+
+## Interaction with Triggers
+
+Action modules often construct trigger callers:
+
+- Items and war specials can return `WarUnitTriggerCaller` with `BaseWarUnitTrigger`.
+- Some item triggers use `raiseType` to allow coexistence with non-item versions.
+
+See `docs/architecture/legacy-engine-triggers.md` for trigger execution rules.
+
+## Open Questions / Follow-ups
+
+- The precise selection rules for personalities and specials depend on
+  `SpecialityHelper` RNG thresholds and scenario overrides; capture those
+  when documenting specific rule packs.
diff --git a/docs/architecture/legacy-engine-logging.md b/docs/architecture/legacy-engine-logging.md
new file mode 100644
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--- /dev/null
+++ b/docs/architecture/legacy-engine-logging.md
@@ -0,0 +1,36 @@
+# Legacy Logging and Versioning
+
+This document summarizes logging utilities and version helpers. References
+include `legacy/hwe/sammo/ActionLogger.php`, `legacy/hwe/sammo/UserLogger.php`,
+and `legacy/hwe/sammo/VersionGitDynamic.php`.
+
+## ActionLogger
+
+`ActionLogger` aggregates logs for a general, nation, and global context:
+
+- Buffers multiple log channels:
+  - General history/action/battle logs
+  - National history logs
+  - Global history/action logs
+- Supports formatted prefixes (`PLAIN`, `YEAR_MONTH`, `NOTICE`, etc.).
+- `flush()` emits buffered logs via helper functions
+  (`pushGeneralHistoryLog`, `pushGlobalHistoryLog`, etc.).
+
+It is used throughout command execution, battle resolution, and event actions.
+
+## UserLogger
+
+`UserLogger` writes user-scoped logs to `user_record`:
+
+- Used for inheritance point spending/awards and other user-level events.
+- `push($text, $type)` buffers entries; `flush()` inserts into DB with
+  `{user_id, server_id, year, month, date, text}`.
+
+## Version Helpers
+
+`VersionGitDynamic` exposes runtime Git metadata:
+
+- `getVersion()` calls `git describe --long --tags` and `git branch`.
+- `getHash()` calls `git rev-parse HEAD`.
+
+These are used for diagnostic display and do not affect gameplay logic.
diff --git a/docs/architecture/legacy-engine-pools.md b/docs/architecture/legacy-engine-pools.md
new file mode 100644
index 0000000..991271c
--- /dev/null
+++ b/docs/architecture/legacy-engine-pools.md
@@ -0,0 +1,43 @@
+# Legacy General Pools
+
+This document summarizes the general pool system used for character selection
+and event-driven recruitment. References include `legacy/hwe/sammo/AbsGeneralPool.php`,
+`legacy/hwe/sammo/AbsFromUserPool.php`, and `legacy/hwe/sammo/GeneralPool/*`.
+
+## Core Abstractions
+
+- `AbsGeneralPool`
+  - Wraps a `Scenario\GeneralBuilder` and a raw `info` payload.
+  - Provides `getGeneralBuilder()`, `getInfo()`, and `occupyGeneralName()`.
+  - Abstract method: `pickGeneralFromPool(...)`.
+
+- `AbsFromUserPool`
+  - Implements reservation logic backed by the `select_pool` table.
+  - Reserves candidates for a user (`owner`) until `reserved_until`.
+  - On selection, clears reservation and binds `general_id`.
+
+## Pool Implementations
+
+- `GeneralPool/RandomNameGeneral`
+  - Generates random names using `GameConst::$randGen*` lists.
+  - Checks duplicate counts and appends suffixes if needed.
+  - Inserts reservation rows into `select_pool` for user selection.
+
+- `GeneralPool/SPoolUnderU30`
+  - Loads a curated pool from `GeneralPool/Pool/UnderS30.json`.
+  - Inserts rows into `select_pool` with pre-defined stats and specials.
+
+## Data Model
+
+`select_pool` table fields (observed usage):
+
+- `unique_name` (pool key)
+- `info` (JSON: stats, portrait, specials, dex, etc.)
+- `owner` (reservation user id)
+- `reserved_until` (reservation expiry)
+- `general_id` (assigned after creation)
+
+## RNG Notes
+
+Pool selection uses injected `RandUtil` to choose candidates and generate
+random names; deterministic seeding depends on caller context.
diff --git a/docs/architecture/legacy-engine-server-env.md b/docs/architecture/legacy-engine-server-env.md
new file mode 100644
index 0000000..429a22d
--- /dev/null
+++ b/docs/architecture/legacy-engine-server-env.md
@@ -0,0 +1,25 @@
+# Legacy Server Environment
+
+This document captures the legacy server-level environment settings and
+utilities. References include `legacy/hwe/sammo/ServerDefaultEnv.php`,
+`legacy/hwe/sammo/ServerEnv.php`, and `legacy/hwe/sammo/ServerTool.php`.
+
+## Server Environment
+
+- `ServerDefaultEnv` holds server-wide constants (e.g.,
+  `maxGeneralsPerMinute`).
+- `ServerEnv` extends `ServerDefaultEnv` and is overridden by
+  `d_setting/ServerEnv.php` when present.
+
+## Turn Term Management
+
+`ServerTool::changeServerTerm($turnterm)` adjusts the global turn length:
+
+1. Validates that `turnterm` divides 120 minutes.
+2. Acquires the game lock (`tryLock()`), unless `ignoreLock` is set.
+3. Recomputes each general's `turntime` based on the new interval.
+4. Updates `game_env.turnterm` and `game_env.starttime`.
+5. Broadcasts a global history notice about the change.
+
+This is a direct mutation of runtime schedule and should be treated as an
+administrative operation.
diff --git a/docs/architecture/legacy-engine.md b/docs/architecture/legacy-engine.md
index 400d964..09eaa12 100644
--- a/docs/architecture/legacy-engine.md
+++ b/docs/architecture/legacy-engine.md
@@ -45,3 +45,14 @@ organization rather than endpoint-first routing.
 - Command catalog: `docs/architecture/legacy-commands.md`
 - Scenario system and rule sets: `docs/architecture/legacy-scenarios.md`
 - Inheritance points (유산 포인트): `docs/architecture/legacy-inherit-points.md`
+- Event system (dynamic/static): `docs/architecture/legacy-engine-events.md`
+- Economy and monthly updates: `docs/architecture/legacy-engine-economy.md`
+- Auctions and betting: `docs/architecture/legacy-engine-auction.md`
+- Items, specials, and traits: `docs/architecture/legacy-engine-items.md`
+- City data and helpers: `docs/architecture/legacy-engine-city.md`
+- Diplomacy and messaging: `docs/architecture/legacy-engine-diplomacy.md`
+- Constraint system: `docs/architecture/legacy-engine-constraints.md`
+- Game constants and unit sets: `docs/architecture/legacy-engine-constants.md`
+- Server environment tools: `docs/architecture/legacy-engine-server-env.md`
+- Logging and versioning: `docs/architecture/legacy-engine-logging.md`
+- General pools: `docs/architecture/legacy-engine-pools.md`
diff --git a/docs/architecture/todo.md b/docs/architecture/todo.md
index 32e1496..fdee661 100644
--- a/docs/architecture/todo.md
+++ b/docs/architecture/todo.md
@@ -35,3 +35,5 @@ Move items into the main docs once they are finalized.
 - [AI suggestion] Expand monthly pipeline details (`preUpdateMonthly`, `postUpdateMonthly`, `turnDate`, `checkStatistic`) with concrete side effects and tables touched.
 - [AI suggestion] Document `ConquerCity()` resolution paths (nation collapse, officer handling, reward/penalty rules).
 - [AI suggestion] Clarify command prefix semantics (`che_`, `cr_`, `event_`) and add per-command effect summaries.
+- [AI suggestion] Document `event` table schema and the static event handler map (`GameConst::$staticEventHandlers`) with command hook examples.
+- [AI suggestion] Document auction scheduling (`registerAuction` call sites) and lifecycle timing rules.