diff --git a/docs/architecture/legacy-engine.md b/docs/architecture/legacy-engine.md
index 09eaa12..26f43a4 100644
--- a/docs/architecture/legacy-engine.md
+++ b/docs/architecture/legacy-engine.md
@@ -37,6 +37,7 @@ organization rather than endpoint-first routing.
 
 ## Detailed Notes
 
+- Entity and schema overview: `docs/architecture/legacy-entities.md`
 - Turn execution pipeline: `docs/architecture/legacy-engine-execution.md`
 - General model and action stack: `docs/architecture/legacy-engine-general.md`
 - General AI behavior and policy model: `docs/architecture/legacy-engine-ai.md`
diff --git a/docs/architecture/legacy-entities.md b/docs/architecture/legacy-entities.md
new file mode 100644
index 0000000..ea026a3
--- /dev/null
+++ b/docs/architecture/legacy-entities.md
@@ -0,0 +1,432 @@
+# Legacy Entities Overview
+
+This document summarizes the primary entities in the legacy engine, how they
+interact, and where their state lives. The active runtime lives in
+`legacy/hwe/sammo/` and uses the tables in `legacy/hwe/sql/schema.sql`.
+
+## Data Sources
+
+- Table name map: `legacy/hwe/sammo/Enums/TableName.php`
+- Schema definitions: `legacy/hwe/sql/schema.sql`
+
+## Coverage Notes
+
+- The legacy runtime mixes active, archived, and transitional tables.
+- Table relationships are mostly enforced in code; few explicit FK constraints.
+- Some tables are retained for history or migration and may not be touched in
+  the current runtime path.
+
+## Core Entities
+
+### General (장수)
+
+- Class: `legacy/hwe/sammo/General.php` (base: `legacy/hwe/sammo/GeneralBase.php`)
+- Tables: `general`, `general_turn`, `rank_data`, `general_access_log`
+- Interaction highlights:
+  - Command execution: `legacy/hwe/sammo/Command/*` and
+    `legacy/hwe/sammo/TurnExecutionHelper.php`
+  - Turn reservation: `legacy/hwe/sammo/LastTurn.php`
+  - Combat adapter: `legacy/hwe/sammo/WarUnitGeneral.php`
+  - Modifiers/triggers via `iAction` modules (items, specials, traits)
+  - Logging: `legacy/hwe/sammo/ActionLogger.php`
+- DB fields (schema):
+  - `general`: no, owner, npcmsg, npc, npc_org, affinity, bornyear, deadyear,
+    newmsg, picture, imgsvr, name, owner_name, nation, city, troop, leadership,
+    leadership_exp, strength, strength_exp, intel, intel_exp, injury,
+    experience, dedication, dex1, dex2, dex3, dex4, dex5, officer_level,
+    officer_city, permission, gold, rice, crew, crewtype, train, atmos, weapon,
+    book, horse, item, turntime, recent_war, makelimit, killturn, block,
+    dedlevel, explevel, age, startage, belong, betray, personal, special,
+    specage, special2, specage2, defence_train, tnmt, myset, tournament,
+    newvote, last_turn, aux, penalty
+  - `general_turn`: id, general_id, turn_idx, action, arg, brief
+  - `general_access_log`: id, general_id, user_id, last_refresh, refresh,
+    refresh_total, refresh_score, refresh_score_total
+  - `rank_data`: id, nation_id, general_id, type, value
+  - JSON columns: `general.last_turn`, `general.aux`, `general.penalty`
+
+### Nation (국가)
+
+- Data rows: `nation`, `nation_env`, `nation_turn`
+- Nation-type actions: `legacy/hwe/sammo/ActionNationType/*`,
+  base in `legacy/hwe/sammo/BaseNation.php`
+- Interaction highlights:
+  - Nation commands: `legacy/hwe/sammo/Command/Nation/*`
+  - Diplomacy: `diplomacy`, `ng_diplomacy`, and
+    `legacy/hwe/sammo/DiplomaticMessage.php`
+  - Monthly economy updates: `legacy/hwe/sammo/Event/Action/*`
+- DB fields (schema):
+  - `nation`: nation, name, color, capital, capset, gennum, gold, rice, bill,
+    rate, rate_tmp, secretlimit, chief_set, scout, war, strategic_cmd_limit,
+    surlimit, tech, power, spy, level, type, aux
+  - `nation_turn`: id, nation_id, officer_level, turn_idx, action, arg, brief
+  - `nation_env`: id, namespace, key, value
+  - JSON columns: `nation.spy`, `nation.aux`, `nation_turn.arg`,
+    `nation_env.value`
+
+### City (도시)
+
+- Data rows: `city`
+- Static map data: `legacy/hwe/sammo/CityConstBase.php`,
+  `legacy/hwe/sammo/CityInitialDetail.php`
+- Live cache: `legacy/hwe/sammo/CityHelper.php`
+- Interaction highlights:
+  - Supply and isolation updates via `Event/Action/UpdateCitySupply`
+  - Conquest/war defender: `legacy/hwe/sammo/WarUnitCity.php`
+- DB fields (schema):
+  - `city`: city, name, level, nation, supply, front, pop, pop_max, agri,
+    agri_max, comm, comm_max, secu, secu_max, trust, trade, dead, def, def_max,
+    wall, wall_max, officer_set, state, region, term, conflict
+  - JSON columns: `city.conflict`
+
+### Troop (부대)
+
+- Data rows: `troop`
+- Interaction highlights:
+  - Join/leave flows in `legacy/hwe/sammo/API/Troop/*`
+  - Static event hooks from `legacy/hwe/sammo/StaticEvent/*`
+- DB fields (schema):
+  - `troop`: troop_leader, nation, name
+
+### Command / Turn (턴 예약과 실행)
+
+- Turn snapshots: `legacy/hwe/sammo/LastTurn.php`
+- General commands: `legacy/hwe/sammo/Command/General/*`
+- Nation commands: `legacy/hwe/sammo/Command/Nation/*`
+- Execution entry: `legacy/hwe/sammo/TurnExecutionHelper.php` and
+  `legacy/hwe/proc.php`
+- DB fields (schema):
+  - `general_turn`: id, general_id, turn_idx, action, arg, brief
+  - `nation_turn`: id, nation_id, officer_level, turn_idx, action, arg, brief
+
+### War Units (전투 단위)
+
+- Base: `legacy/hwe/sammo/WarUnit.php`
+- General combat: `legacy/hwe/sammo/WarUnitGeneral.php`
+- City combat: `legacy/hwe/sammo/WarUnitCity.php`
+- Interaction highlights:
+  - Battle flow and resolution: `legacy/hwe/process_war.php`
+  - Uses General/Nation/City snapshots for deterministic resolution
+
+## Rule Modules and Modifiers
+
+### iAction Modules
+
+- Interface: `legacy/hwe/sammo/iAction.php`
+- Modules:
+  - Items: `legacy/hwe/sammo/ActionItem/*`
+  - Domestic specials: `legacy/hwe/sammo/ActionSpecialDomestic/*`
+  - War specials: `legacy/hwe/sammo/ActionSpecialWar/*`
+  - Personalities: `legacy/hwe/sammo/ActionPersonality/*`
+  - Nation types: `legacy/hwe/sammo/ActionNationType/*`
+  - Crew types: `legacy/hwe/sammo/ActionCrewType/*`
+  - Scenario effects: `legacy/hwe/sammo/ActionScenarioEffect/*`
+- Applied by `General::getActionList()` and used by triggers, stat calculation,
+  and combat phases.
+
+### Trigger System
+
+- Trigger callers: `legacy/hwe/sammo/TriggerCaller.php`,
+  `legacy/hwe/sammo/GeneralTriggerCaller.php`,
+  `legacy/hwe/sammo/WarUnitTriggerCaller.php`
+- Trigger definitions: `legacy/hwe/sammo/GeneralTrigger/*`,
+  `legacy/hwe/sammo/WarUnitTrigger/*`
+- Used in pre-turn processing and battle phases.
+
+### Constraints
+
+- Validation rules: `legacy/hwe/sammo/Constraint/*`
+- Command prechecks and selection logic use these constraints.
+
+## System Entities
+
+### Events
+
+- Dynamic events: `event` table, executed by `legacy/hwe/sammo/Event/*`
+- Static hooks: `legacy/hwe/sammo/StaticEvent/*`,
+  wired via `GameConst::$staticEventHandlers`
+- DB fields (schema):
+  - `event`: id, target, priority, condition, action
+  - JSON columns: `event.condition`, `event.action`
+
+### Messaging and Diplomacy
+
+- Messages: `legacy/hwe/sammo/Message.php`
+- Targets: `legacy/hwe/sammo/MessageTarget.php`,
+  `legacy/hwe/sammo/Target.php`
+- Diplomacy wrapper: `legacy/hwe/sammo/DiplomaticMessage.php`
+- Table: `message`
+- DB fields (schema):
+  - `message`: id, mailbox, type, src, dest, time, valid_until, message
+  - `diplomacy`: no, me, you, state, term, dead, showing
+  - `ng_diplomacy`: no, src_nation_id, dest_nation_id, prev_no, state,
+    text_brief, text_detail, date, src_signer, dest_signer, aux
+  - JSON columns: `message.message`, `ng_diplomacy.aux`
+
+### Economy and World State
+
+- Monthly updates: `legacy/hwe/sammo/Event/Action/ProcessIncome`,
+  `ProcessSemiAnnual`, `ProcessWarIncome`
+- Trade and supply: `RandomizeCityTradeRate`, `UpdateCitySupply`,
+  `UpdateNationLevel`
+- DB fields (schema):
+  - `nation_env`: id, namespace, key, value
+  - `statistic`: no, year, month, nation_count, nation_name, nation_hist,
+    gen_count, personal_hist, special_hist, power_hist, crewtype, etc, aux
+  - JSON columns: `statistic.aux`, `nation_env.value`
+
+### Auctions, Betting, and Votes
+
+- Auctions: `legacy/hwe/sammo/Auction.php` and `ng_auction*` tables
+- Betting: `legacy/hwe/sammo/Betting.php` and `ng_betting`
+- Votes and tournaments: `vote`, `vote_comment`, `tournament`
+- DB fields (schema):
+  - `ng_auction`: id, type, finished, target, host_general_id, req_resource,
+    open_date, close_date, detail
+  - `ng_auction_bid`: no, auction_id, owner, general_id, amount, date, aux
+  - `ng_betting`: id, betting_id, general_id, user_id, betting_type, amount
+  - `vote`: id, vote_id, general_id, nation_id, selection
+  - `vote_comment`: id, vote_id, general_id, nation_id, general_name,
+    nation_name, text, date
+  - `tournament`: seq, no, npc, name, w, b, h, leadership, strength, intel, lvl,
+    grp, grp_no, win, draw, lose, gl, prmt
+  - JSON columns: `ng_auction.detail`, `ng_auction_bid.aux`, `ng_betting.betting_type`,
+    `vote.selection`
+
+### Logs and Records
+
+- Action logs: `legacy/hwe/sammo/ActionLogger.php`
+- User logs: `legacy/hwe/sammo/UserLogger.php`
+- Tables: `ng_history`, `world_history`, `general_record`, `user_record`, `hall`
+- DB fields (schema):
+  - `ng_history`: no, server_id, year, month, map, global_history, global_action,
+    nations
+  - `world_history`: id, nation_id, year, month, text
+  - `general_record`: id, general_id, log_type, year, month, text
+  - `user_record`: id, user_id, server_id, log_type, year, month, date, text
+  - `hall`: id, server_id, season, scenario, general_no, type, value, owner, aux
+  - JSON columns: `ng_history.map`, `ng_history.global_history`,
+    `ng_history.global_action`, `ng_history.nations`, `hall.aux`
+
+### Boards, Locks, and Storage
+
+- Boards/comments: `board`, `comment`
+- Locks: `plock`
+- KV stores: `storage`, `nation_env`
+- DB fields (schema):
+  - `board`: no, nation_no, is_secret, date, general_no, author, author_icon,
+    title, text
+  - `comment`: no, nation_no, is_secret, date, document_no, general_no, author,
+    text
+  - `plock`: no, type, plock, locktime
+  - `storage`: id, namespace, key, value
+  - JSON columns: `storage.value`
+
+### Archive and Lifecycle Tables
+
+- Archive/season data: `ng_games`, `ng_old_nations`, `ng_old_generals`,
+  `emperior`
+- Scheduling: `reserved_open`
+- Selection pools: `select_npc_token`, `select_pool`
+- Inheritance: `inheritance_result`
+- DB fields (schema):
+  - `ng_games`: id, server_id, date, winner_nation, map, season, scenario,
+    scenario_name, env
+  - `ng_old_nations`: id, server_id, nation, data, date
+  - `ng_old_generals`: id, server_id, general_no, owner, name, last_yearmonth,
+    turntime, data
+  - `emperior`: no, server_id, phase, nation_count, nation_name, nation_hist,
+    gen_count, personal_hist, special_hist, name, type, color, year, month,
+    power, gennum, citynum, pop, poprate, gold, rice, l12name, l12pic, l11name,
+    l11pic, l10name, l10pic, l9name, l9pic, l8name, l8pic, l7name, l7pic,
+    l6name, l6pic, l5name, l5pic, tiger, eagle, gen, history, aux
+  - `reserved_open`: id, options, date
+  - `select_npc_token`: id, owner, valid_until, pick_more_from, pick_result,
+    nonce
+  - `select_pool`: id, unique_name, owner, general_id, reserved_until, info
+  - `inheritance_result`: id, server_id, owner, general_id, year, month, value
+  - JSON columns: `ng_games.env`, `ng_old_nations.data`, `ng_old_generals.data`,
+    `emperior.history`, `emperior.aux`, `reserved_open.options`,
+    `select_npc_token.pick_result`, `inheritance_result.value`
+
+## Aux and JSON Payloads
+
+Legacy data uses many JSON fields with dynamic keys. Most are updated in code,
+not enforced by DB constraints.
+
+### General `aux`
+
+- Storage layer: `legacy/hwe/sammo/LazyVarAndAuxUpdater.php`
+- Access pattern: `getAuxVar()` / `setAuxVar()` on `General`
+- Literal keys observed in code (not exhaustive):
+  - `armType`, `autorun_limit`, `inheritBuff`, `inheritRandomUnique`,
+    `inheritResetSpecialWar`, `inheritResetTurnTime`,
+    `inheritSpecificSpecialWar`, `last발령`, `max_domestic_critical`,
+    `movingTargetCityID`, `nextTurnTimeBase`, `pickYearMonth`,
+    `use_auto_nation_turn`, `use_treatment`
+- Key sources:
+  - Turn execution timing: `legacy/hwe/sammo/TurnExecutionHelper.php`
+  - AI state and movement: `legacy/hwe/sammo/GeneralAI.php`
+  - Inheritance actions: `legacy/hwe/sammo/API/InheritAction/*`
+  - Domestic critical resets: `legacy/hwe/sammo/Command/General/*`
+  - Troop dispatch markers: `legacy/hwe/sammo/Command/Nation/che_발령.php`
+- Item or trigger-specific keys are stored via constants (e.g.
+  `ActionItem/event_충차.php`, `WarUnitTrigger/event_충차아이템소모.php`) and are
+  not visible in literal scans.
+
+### Nation `aux`
+
+- Enum keys: `legacy/hwe/sammo/Enums/NationAuxKey.php`
+  - `can_국기변경`, `can_국호변경`, `did_특성초토화`, `can_무작위수도이전`,
+    `can_대검병사용`, `can_극병사용`, `can_화시병사용`, `can_원융노병사용`,
+    `can_산저병사용`, `can_상병사용`, `can_음귀병사용`, `can_무희사용`,
+    `can_화륜차사용`
+- Used by constraints and nation commands, especially unit unlock logic.
+
+### Other JSON Columns
+
+- `city.conflict`: siege contribution map keyed by nation id.
+- `message.message`: serialized message payload including targets/options.
+- `event.condition` / `event.action`: JSON DSL for event dispatch.
+- `storage.value` / `nation_env.value`: key-value JSON via `KVStorage`
+  (`legacy/src/sammo/KVStorage.php`), used for `game_env`, `nation_env`,
+  `betting`, `vote`, `inheritance_*`, and other namespaces.
+- Large history blobs: `ng_history.*`, `ng_old_nations.data`,
+  `ng_old_generals.data`, `emperior.history`, `emperior.aux`.
+
+### KVStorage `game_env` Namespace
+
+`game_env` is stored in `storage` with `namespace = 'game_env'` and is the
+primary server-wide runtime state store. Keys are read/written in core
+functions and APIs (e.g. `legacy/hwe/func.php`,
+`legacy/hwe/func_time_event.php`, `legacy/hwe/sammo/TurnExecutionHelper.php`).
+
+Observed literal keys (from code reads/writes, non-exhaustive):
+
+- Time and turn: `startyear`, `year`, `month`, `init_year`, `init_month`,
+  `starttime`, `opentime`, `turntime`, `turnterm`
+- Scenario and season: `scenario`, `scenario_text`, `season`
+- Join and creation gates: `join_mode`, `maxgeneral`, `block_general_create`,
+  `show_img_level`, `icon_path`, `extended_general`
+- Global flags and limits: `isunited`, `fiction`, `autorun_user`, `killturn`,
+  `refresh`, `maxrefresh`, `refreshLimit`, `maxonline`, `recentTraffic`,
+  `online_user_cnt`, `online_nation`, `server_cnt`, `msg`
+- NPC policy: `npcmode`, `npc_nation_policy`, `npc_general_policy`
+- Tournament and voting: `tournament`, `phase`, `tnmt_type`, `tnmt_time`,
+  `tnmt_auto`, `tnmt_msg`, `tnmt_trig`, `tnmt_pattern`, `develcost`,
+  `last_tournament_betting_id`, `lastVote`
+- Scout restrictions: `block_change_scout`
+- Auctions: `obfuscatedNamePool`
+
+Notes:
+
+- Some keys are used as feature toggles (e.g. `block_change_scout`,
+  `block_general_create`) while others carry time/season state.
+- Additional keys may exist via dynamic or computed names outside literal
+  scans, especially in admin or migration scripts.
+
+## Table Usage Index (Partial)
+
+This index focuses on primary runtime touch points and omits view-only pages.
+
+- `general`: `legacy/hwe/sammo/General.php`, `legacy/hwe/sammo/GeneralAI.php`,
+  `legacy/hwe/sammo/TurnExecutionHelper.php`
+- `general_turn`: `legacy/hwe/sammo/TurnExecutionHelper.php`,
+  `legacy/hwe/sammo/API/Command/GetReservedCommand.php`
+- `general_access_log`: `legacy/hwe/sammo/General.php`,
+  `legacy/hwe/sammo/API/General/GetFrontInfo.php`
+- `rank_data`: `legacy/hwe/sammo/General.php`, `legacy/hwe/sammo/WarUnitGeneral.php`
+- `nation`: `legacy/hwe/sammo/Command/Nation/*`,
+  `legacy/hwe/sammo/Scenario/Nation.php`
+- `nation_turn`: `legacy/hwe/sammo/TurnExecutionHelper.php`,
+  `legacy/hwe/sammo/API/NationCommand/GetReservedCommand.php`
+- `nation_env`: `legacy/src/sammo/KVStorage.php`,
+  `legacy/hwe/sammo/Command/NationCommand.php`
+- `city`: `legacy/hwe/sammo/CityHelper.php`,
+  `legacy/hwe/sammo/WarUnitCity.php`, `legacy/hwe/process_war.php`
+- `troop`: `legacy/hwe/sammo/API/Troop/*`,
+  `legacy/hwe/sammo/StaticEvent/*`
+- `diplomacy`, `ng_diplomacy`: `legacy/hwe/sammo/DiplomaticMessage.php`,
+  `legacy/hwe/sammo/API/Global/GetDiplomacy.php`
+- `message`: `legacy/hwe/sammo/Message.php`,
+  `legacy/hwe/sammo/API/Message/*`
+- `event`: `legacy/hwe/sammo/TurnExecutionHelper.php`,
+  `legacy/hwe/sammo/Event/*`
+- `board`, `comment`: `legacy/hwe/v_board.php`,
+  `legacy/hwe/j_board_get_articles.php`
+- `ng_auction`, `ng_auction_bid`: `legacy/hwe/sammo/Auction.php`,
+  `legacy/hwe/sammo/API/Auction/*`
+- `ng_betting`: `legacy/hwe/sammo/Betting.php`,
+  `legacy/hwe/sammo/API/Betting/*`
+- `vote`, `vote_comment`: `legacy/hwe/sammo/API/Vote/*`,
+  `legacy/hwe/v_vote.php`
+- `ng_history`, `world_history`: `legacy/hwe/sammo/ActionLogger.php`,
+  `legacy/hwe/func_history.php`
+- `general_record`: `legacy/hwe/sammo/ActionLogger.php`
+- `user_record`: `legacy/hwe/sammo/UserLogger.php`
+- `storage`: `legacy/src/sammo/KVStorage.php`,
+  `legacy/hwe/sammo/ResetHelper.php`
+- `ng_games`, `ng_old_nations`, `ng_old_generals`, `emperior`:
+  `legacy/hwe/sammo/ResetHelper.php`, `legacy/hwe/a_emperior.php`
+
+## Interaction Sketch
+
+- Turn execution (`TurnExecutionHelper`):
+  - Reads `general_turn` / `nation_turn`
+  - Builds General/Nation/City context
+  - Applies constraints → runs command → triggers → logs
+  - Runs monthly events and world updates
+- Battle (`process_war.php`):
+  - Builds `WarUnitGeneral` and `WarUnitCity`
+  - Resolves phases and damage with triggers
+  - Applies city conquest and nation collapse rules
+- Diplomacy:
+  - `Message` delivers a diplomacy request
+  - `DiplomaticMessage` accepts/rejects
+  - Nation command executes and updates diplomacy tables
+
+## Entity Relationships (Mermaid ERD)
+
+Note: `message.src` / `message.dest` are polymorphic in practice (general or
+nation depending on message type). The diagram below treats them as general
+links for simplicity.
+
+```mermaid
+erDiagram
+    GENERAL ||--o{ GENERAL_TURN : reserves
+    GENERAL ||--o{ GENERAL_ACCESS_LOG : logs
+    GENERAL ||--o{ GENERAL_RECORD : records
+    GENERAL ||--o{ RANK_DATA : ranks
+    GENERAL ||--o{ MESSAGE : sends
+    GENERAL ||--o{ MESSAGE : receives
+    GENERAL ||--o{ VOTE : votes
+    GENERAL ||--o{ VOTE_COMMENT : comments
+    GENERAL ||--o{ NG_BETTING : bets
+    GENERAL ||--o{ NG_AUCTION : hosts
+    GENERAL ||--o{ NG_AUCTION_BID : bids
+    GENERAL ||--o{ TROOP : leads
+
+    NATION ||--o{ GENERAL : has
+    NATION ||--o{ NATION_TURN : schedules
+    NATION ||--o{ CITY : owns
+    NATION ||--o{ DIPLOMACY : relates
+    NATION ||--o{ NG_DIPLOMACY : documents
+    NATION ||--o{ BOARD : boards
+    NATION ||--o{ COMMENT : comments
+    NATION ||--o{ WORLD_HISTORY : history
+
+    CITY ||--o{ GENERAL : hosts
+
+    BOARD ||--o{ COMMENT : comments
+
+    NG_AUCTION ||--o{ NG_AUCTION_BID : bids
+```
+
+## Related Docs
+
+- `docs/architecture/legacy-engine.md`
+- `docs/architecture/legacy-engine-general.md`
+- `docs/architecture/legacy-engine-war.md`
+- `docs/architecture/legacy-engine-economy.md`
+- `docs/architecture/legacy-engine-diplomacy.md`
+- `docs/architecture/legacy-engine-events.md`
diff --git a/docs/architecture/overview.md b/docs/architecture/overview.md
index 9cf754e..fc495d4 100644
--- a/docs/architecture/overview.md
+++ b/docs/architecture/overview.md
@@ -22,6 +22,11 @@ monorepo plan is prepared alongside it.
 - Scenario and unit pack data are loaded from `legacy/hwe/scenario/`
 - Deterministic RNG is required for gameplay outcomes
 
+## Legacy Docs
+
+- Legacy entities and DB schema overview: `docs/architecture/legacy-entities.md`
+- Legacy engine map: `docs/architecture/legacy-engine.md`
+
 ## Cross-Cutting Policies
 
 - No ad-hoc randomness for gameplay; use deterministic RNG