diff --git a/shared/src/constants.ts b/shared/src/constants.ts
index ed9edc8..3b5c0e0 100644
--- a/shared/src/constants.ts
+++ b/shared/src/constants.ts
@@ -16,6 +16,11 @@ export const HUNGER_THRESHOLD = 30;
 export const ENERGY_THRESHOLD = 20;
 export const NEED_RECOVERY_RATE = 0.5;
 
+// Productivity need
+export const PRODUCTIVITY_DECAY_PER_TICK = 0.02;
+export const PRODUCTIVITY_THRESHOLD = 40;
+export const PRODUCTIVITY_RECOVERY_RATE = 0.5;
+
 // Day/night cycle
 export const DAY_NIGHT_RATIO = 2;           // day is 2x as long as night
 export const DAY_HOURS = 12;                // game hours of daytime
@@ -78,6 +83,7 @@ export const Terrain = {
   GRASS: 0,
   WATER: 1,
   DIRT: 2,
+  STONE: 3,
 } as const;
 export type Terrain = (typeof Terrain)[keyof typeof Terrain];
 
diff --git a/shared/src/types.ts b/shared/src/types.ts
index 02e39a1..61a181b 100644
--- a/shared/src/types.ts
+++ b/shared/src/types.ts
@@ -23,7 +23,7 @@ export interface MemoryEvent {
   detail: string;
   oldTier?: string;
   newTier?: string;
-  need?: 'hunger' | 'energy';
+  need?: 'hunger' | 'energy' | 'productivity';
   oldGoal?: string;
   newGoal?: string;
 }
@@ -48,6 +48,7 @@ export interface Appearance {
 export interface Needs {
   hunger: number; // 0-100
   energy: number; // 0-100
+  productivity: number; // 0-100
 }
 
 export interface Stats {
@@ -78,7 +79,7 @@ export interface StatModifiers {
 }
 
 export type MovementState = 'idle' | 'walking';
-export type GoalType = 'wander' | 'eat' | 'rest';
+export type GoalType = 'wander' | 'eat' | 'rest' | 'gather';
 
 export interface Movement {
   state: MovementState;
@@ -96,6 +97,7 @@ export interface PlayerControlled {
 export interface NPCBrain {
   currentGoal: GoalType | null;
   goalQueue: GoalType[];
+  gatherTarget?: { x: number; y: number; resourceType: string } | null;
 }
 
 export type InteractionPhase = 'none' | 'facing' | 'pausing' | 'emoting' | 'proposing';
@@ -141,6 +143,7 @@ export interface EntityState {
   playerControlled?: PlayerControlled;
   name?: string; // NPC display name
   backstory?: string;
+  inventory?: Record<string, number>;
   socialState?: {
     phase: InteractionPhase;
     partnerId: EntityId | null;
@@ -166,6 +169,7 @@ export interface WorldState {
   terrain: number[];            // flat array [y * width + x], terrain type per tile
   decorations: number[];        // flat array [y * width + x], decoration tile index (-1 = none)
   trunkDecorations: number[];   // flat array [y * width + x], trunk tile index (-1 = none)
+  resourceTiles: Array<{ x: number; y: number; resourceType: string }>;
 }
 
 export interface StateUpdate {