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diff --git a/worldbuilding_guide/README.md b/worldbuilding_guide/README.md
index b6f6de8..97cf43b 100644
--- a/worldbuilding_guide/README.md
+++ b/worldbuilding_guide/README.md
@@ -22,4 +22,6 @@ The House of Icarus is data-driven. Everything — rooms, items, mobs, objects,
 | [Toggles](toggles.md) | Player toggle options (tiny_map, xp_drops, automap, etc.) |
 | [Search](search.md) | The search command and searchable items |
 | [Hidden Objects](hidden_objects.md) | Hidden interactive objects |
+| [Bank](bank.md) | Bank system — deposit, withdraw, browse, bank booth placement |
+| [Construction](construction.md) | Construction skill — planks, furniture, houses, sawmill, Plank Make |
 | [Tips](tips.md) | Practical tips for building a world |
diff --git a/worldbuilding_guide/bank.md b/worldbuilding_guide/bank.md
new file mode 100644
index 0000000..0a5ec88
--- /dev/null
+++ b/worldbuilding_guide/bank.md
@@ -0,0 +1,68 @@
+# Bank System
+
+The bank system allows players to store items permanently, freeing up inventory space.
+
+## Objects
+
+### bank_booth
+
+A bank terminal that players can interact with. Has no special behavior — the `bank` command checks for any `bank_booth` object in the room.
+
+```yaml
+id: bank_booth
+name: bank booth
+color: "226"
+description: "..."
+inroom_description: "A bank booth is set into the wall."
+```
+
+To place a bank booth in a room, add it to the room's `objects:` list:
+
+```yaml
+objects:
+  - id: bank_booth
+```
+
+## Commands
+
+| Command | Description |
+|---------|-------------|
+| `bank` | Opens bank interface (requires bank booth in room) |
+| `use bank` | Same as `bank` |
+
+### Bank Interface Commands
+
+| Command | Description |
+|---------|-------------|
+| `deposit <item>` | Move item from inventory to bank |
+| `deposit all` | Deposit entire inventory |
+| `withdraw <item>` | Move item from bank to inventory |
+| `browse` / `list` | Show bank contents |
+| `leave` | Exit bank interface |
+
+## Implementation
+
+### Session State
+
+`StateBank` (defined in `internal/net/server.go`) is the session state for the bank interface. Input is routed through `handleBankInput` in `internal/game/cmd_bank.go`.
+
+### Player Storage
+
+Bank items are stored in the `Player.Bank` field (`map[int]*InventorySlot`), saved in character YAML. Bank slots are sequential and reuse freed slots. There is no slot limit.
+
+### Command Dispatch
+
+- `bank` is classified as `ClassActive` in `classifyCommand()`
+- `bank` case in `executeCommand()` calls `doBank(sess)`
+- `doUse()` checks for `"bank"` or `"bank booth"` targets and routes to `doBank()`
+- `doBank()` checks for a `bank_booth` object in the current room
+- `handleBankInput()` dispatches deposit/withdraw/browse/leave commands
+
+### Data Files
+
+| File | Purpose |
+|------|---------|
+| `data/objects/bank_booth.yaml` | Bank booth object definition |
+| `data/help/bank.yaml` | Help topic for the bank system |
+
+Default bank booth locations: Town Square (room 1), Forge (room 12).
diff --git a/worldbuilding_guide/construction.md b/worldbuilding_guide/construction.md
new file mode 100644
index 0000000..799057a
--- /dev/null
+++ b/worldbuilding_guide/construction.md
@@ -0,0 +1,208 @@
+# Construction Skill
+
+The Construction skill allows players to process logs into planks and assemble planks into furniture at a workbench. Higher-tier logs produce more valuable planks and furniture.
+
+## Skill
+
+- Skill name: `construction`
+- Abbreviation: `con`
+- Level range: 1-99
+- XP table: RSC standard
+
+## Commands
+
+| Command | Description |
+|---------|-------------|
+| `construct` / `make` | Open construction menu at a workbench |
+| `construct <item>` | Build a specific item |
+| `construct <qty> <item>` | Build multiple of an item |
+
+## Objects
+
+### workbench
+
+The primary construction station. Placed in rooms to enable construction.
+
+```yaml
+id: workbench
+name: workbench
+color: "172"
+description: "A sturdy wooden workbench..."
+inroom_description: "A workbench stands against the wall..."
+```
+
+### estate_directory
+
+A terminal that shows registered homeowners and lets them enter their house. Handled entirely in Go code (`internal/game/cmd_estate_directory.go`), not via YAML behaviors.
+
+```yaml
+id: estate_directory
+name: Estate Directory
+color: "39"
+description: "A holographic terminal displaying property records..."
+inroom_description: "An estate directory terminal..."
+```
+
+When a player looks at the directory, it scans `data/players/characters/*.yaml` for the `owns_house_local_neighborhood` player flag and lists all homeowners. When a player uses or talks to the directory and owns a house, they can teleport to their house entrance room.
+
+## Tools
+
+### saw
+
+Required tool for cutting logs into planks at the workbench.
+
+```yaml
+id: saw
+name: saw
+tool_type: saw
+value: 30
+```
+
+## Items
+
+### Planks (4 tiers)
+
+| Item ID | Name | Level | Value | Made From |
+|---------|------|-------|-------|-----------|
+| `planks` | planks | 1 | 20 | logs |
+| `oak_planks` | oak planks | 15 | 40 | oak_logs |
+| `teak_planks` | teak planks | 35 | 80 | teak_logs |
+| `mahogany_planks` | mahogany planks | 50 | 120 | mahogany_logs |
+
+### Furniture (sellables)
+
+| Item ID | Level | Planks Required |
+|---------|-------|-----------------|
+| `wooden_shelf` | 4 | 2 planks |
+| `wooden_table` | 6 | 3 planks |
+| `wooden_chair` | 8 | 2 planks |
+| `oak_shelf` | 18 | 2 oak planks |
+| `oak_table` | 20 | 3 oak planks |
+| `teak_table` | 38 | 3 teak planks |
+| `mahogany_table` | 52 | 3 mahogany planks |
+
+## Recipes
+
+All recipes use `type: construction` and `station: [workbench]`. Log-to-plank recipes additionally require `tool: saw`.
+
+Example plank recipe:
+```yaml
+id: construct_oak_planks
+type: construction
+level: 15
+xp: 10
+wait: 20
+station: [workbench]
+tool: saw
+consume:
+  - items: [oak_logs]
+    qty: 1
+output: oak_planks
+message: "You saw the oak logs into sturdy oak planks."
+```
+
+Example furniture recipe:
+```yaml
+id: construct_wooden_table
+type: construction
+level: 6
+xp: 25
+wait: 6
+station: [workbench]
+consume:
+  - items: [planks]
+    qty: 3
+output: wooden_table
+message: "You build a sturdy wooden table."
+```
+
+## NPCs
+
+### estate_broker
+
+Located in room 16 (Construction Site). Talk behavior sells a house plot for 10 credits via `cost` + `set_player_flags`. Sets `owns_house_local_neighborhood: "local_neighborhood"` on purchase.
+
+```yaml
+id: estate_broker
+name: estate broker
+behavior: estate_broker_talk
+unique: true
+```
+
+### sawmill_operator
+
+Located in room 171 (Lumberyard). Talk behavior processes all logs in inventory into planks for a credit fee. Uses the `sawmill: true` node action which triggers `processSawmill()` in `internal/game/action_talk.go`.
+
+Fees: regular (5cr), oak (10cr), teak (20cr), mahogany (40cr).
+
+## Science Mod: Plank Make
+
+Level 86 Science utility mod that converts logs to planks at 70% of sawmill cost. Uses naturejunk, solarjunk, and scrap_metal.
+
+```go
+{ID: "plank_make", Name: "Plank Make", Level: 86, BaseXP: 90.0,
+    JunkCost: map[string]int{"naturejunk": 5, "solarjunk": 1, "scrap_metal": 1},
+    Category: ModUtility, TargetType: "inventory"},
+```
+
+Usage: `trigger plank make` (all logs) or `trigger plank make <log type>` (specific).
+
+## Player Houses
+
+Player houses are real YAML rooms stored in `data/rooms/player_housing/`. Each house area (e.g. Local Neighborhood) has entrance + workshop rooms with unique room IDs in the 200+ range.
+
+House room files follow the same format as world rooms:
+```yaml
+id: 200
+name: "Player House: Entrance Hall"
+description: "..."
+exits:
+  south: 170
+  north: 201
+objects:
+  - id: charging_station
+```
+
+The room loader (`World.LoadRoom`) checks `data/rooms/<id>.yaml` first, then falls back to `data/rooms/player_housing/<id>.yaml`.
+
+Ownership is tracked via player flags (e.g. `owns_house_local_neighborhood: "local_neighborhood"`). The Estate Directory scans character YAML files for these flags.
+
+## Implementation
+
+### Production Integration
+
+Construction is added to `productionTypes` in `action_production.go`:
+```go
+"construction": {"construct", "constructing"},
+```
+
+This enables automatic support through the unified production system (`advanceProduction`, `startProductionFromRecipe`, etc.).
+
+### Command
+
+`cmd_construct.go` follows the same pattern as `cmd_craft.go`, using per-recipe `Station` and `Tool` checks. Station: `workbench`, Tool: `saw` (for plank recipes only).
+
+### Option
+
+`construct_all` (OptBool, default false): Auto-start construction when only one product is available.
+
+## Data File Summary
+
+| Path | Purpose |
+|------|---------|
+| `data/objects/workbench.yaml` | Workbench station object |
+| `data/objects/estate_directory.yaml` | Directory terminal object |
+| `data/items/saw.yaml` | Saw tool |
+| `data/items/planks.yaml` - `mahogany_planks.yaml` | Plank items (4 tiers) |
+| `data/items/wooden_shelf.yaml` - `mahogany_table.yaml` | Furniture items (7 items) |
+| `data/recipes/construct_planks.yaml` - `construct_mahogany_table.yaml` | Construction recipes (11 recipes) |
+| `data/mobs/estate_broker.yaml` | Estate broker mob |
+| `data/mobs/sawmill_operator.yaml` | Sawmill operator mob |
+| `data/behaviors/estate_broker_talk.yaml` | Broker talk behavior |
+| `data/behaviors/sawmill_operator_talk.yaml` | Sawmill operator talk behavior |
+| `data/rooms/16.yaml` | Construction Site (updated) |
+| `data/rooms/170.yaml` | Local Neighborhood |
+| `data/rooms/171.yaml` | Lumberyard |
+| `data/rooms/player_housing/200.yaml` | Player house entrance |
+| `data/rooms/player_housing/201.yaml` | Player house workshop |
+| `data/help/construct.yaml` | Help topic |
diff --git a/worldbuilding_guide/hacking.md b/worldbuilding_guide/hacking.md
new file mode 100644
index 0000000..6f9bf9a
--- /dev/null
+++ b/worldbuilding_guide/hacking.md
@@ -0,0 +1,71 @@
+## Hacking
+
+Hacking minigames are played by jacking into terminal objects. Terminals are YAML objects that are registered in Go's `terminalDefs` map.
+
+### Terminal Object YAML
+
+```yaml
+id: terminal_basic
+name: basic terminal
+color: "40"
+description: "A battered terminal with a cracked screen. {40}[Level 1 Hacking]{/}"
+inroom_description: "A {40}basic terminal{/} hums quietly against the wall."
+```
+
+- `id` must match a key in `terminalDefs` (Go code in `internal/game/hacking.go`)
+- `name` is used for matching in the `jack` command
+- `color` controls the display color
+- `description` is shown when examining the terminal
+- `inroom_description` is shown in room listings
+- No `behavior` field — terminals are registered in Go, not YAML behaviors
+
+### Adding a New Terminal
+
+1. Create an object YAML file in `data/objects/terminal_<name>.yaml`
+2. Add an entry to `terminalDefs` in `internal/game/hacking.go`
+3. Optionally create a new minigame implementation in `internal/game/hacking_<name>.go`
+4. Place the terminal object in a room's `objects:` list
+
+### Adding a New Minigame
+
+New minigames implement the `HackingMinigame` interface:
+
+```go
+type HackingMinigame interface {
+    Init(level int) string
+    HandleInput(input string) (output string, done bool, won bool)
+    Name() string
+}
+```
+
+Optionally implement `XPBonuser` for bonus XP:
+
+```go
+type XPBonuser interface {
+    BonusXP() int
+}
+```
+
+### Agility Courses
+
+Agility courses are defined in `data/courses/<id>.yaml`. Each course defines a sequence of obstacle rooms with specific verbs.
+
+```yaml
+id: "vent_shaft"
+name: "Ventilation Shaft Course"
+required_level: 1
+start_room: 200
+completion_xp: 40
+obstacles:
+  - room_id: 201
+    verb: scramble
+    ticks_per_phase: 2
+    xp: 8
+    fail_damage: [1, 2]
+    messages:
+      - "You approach the corroded ventilation wall..."
+      - "You find footholds in the rusted panels and begin to climb..."
+      - "You scramble up the wall and haul yourself onto the ledge!"
+```
+
+Each obstacle room should have an `on_enter` message telling the player which verb to use, and a `down` exit back to the course hub.
diff --git a/worldbuilding_guide/index.md b/worldbuilding_guide/index.md
index e19c207..9f721cb 100644
--- a/worldbuilding_guide/index.md
+++ b/worldbuilding_guide/index.md
@@ -8,3 +8,7 @@
 | An interactive object (rock, lever, door) | `data/objects/<id>.yaml` |
 | A behavior (mining, dialog, toggle) | `data/behaviors/<id>.yaml` |
 | A shared drop table | `data/drops/<id>.yaml` |
+| A crafting recipe | `data/recipes/<id>.yaml` |
+| A help topic | `data/help/<id>.yaml` |
+| An agility course | `data/courses/<id>.yaml` |
+| A player house | `data/rooms/player_housing/<id>.yaml` |