debuffs

backend/internal/game/engine.go

@@ -1238,6 +1238,18 @@ func (e *Engine) processHeroAttack(cs *model.CombatState, now time.Time) {
 			EnemyHP:       combatEvt.EnemyHP,
 			DebuffApplied: combatEvt.DebuffApplied,
 		})
+		if combatEvt.DebuffApplied != "" {
+			if dt, ok := model.ValidDebuffType(combatEvt.DebuffApplied); ok {
+				if def, ok := model.DebuffDefinition(dt); ok {
+					e.sender.SendToHero(cs.HeroID, "debuff_applied", model.DebuffAppliedPayload{
+						DebuffType: string(dt),
+						DurationMs: def.Duration.Milliseconds(),
+						Magnitude:  def.Magnitude,
+						ExpiresAt:  now.Add(def.Duration),
+					})
+				}
+			}
+		}
 	}
 
 	if !cs.Enemy.IsAlive() {

backend/internal/model/ws_message.go

@@ -1,6 +1,9 @@
 package model
 
-import "encoding/json"
+import (
+	"encoding/json"
+	"time"
+)
 
 // WSEnvelope is the wire format for all WebSocket messages (both directions).
 type WSEnvelope struct {
@@ -200,6 +203,14 @@ type BuffAppliedPayload struct {
 	Magnitude float64 `json:"magnitude"`
 }
 
+// DebuffAppliedPayload is sent when a debuff is applied to the hero.
+type DebuffAppliedPayload struct {
+	DebuffType string    `json:"debuffType"`
+	DurationMs int64     `json:"durationMs"`
+	Magnitude  float64   `json:"magnitude,omitempty"`
+	ExpiresAt  time.Time `json:"expiresAt"`
+}
+
 // ErrorPayload is sent when a client command fails validation.
 type ErrorPayload struct {
 	Code    string `json:"code"`

frontend/src/game/engine.ts

@@ -9,6 +9,8 @@ import type {
   NearbyHeroData,
   NPCData,
   BuildingData,
+  ActiveDebuff,
+  DebuffType,
 } from './types';
 import { GamePhase } from './types';
 import { GameRenderer, worldToScreen } from './renderer';
@@ -620,6 +622,38 @@ export class GameEngine {
     this._notifyStateChange();
   }
 
+  /** Apply or refresh a single debuff from WS. */
+  applyDebuffApplied(type: DebuffType, durationMs: number, expiresAtMs?: number): void {
+    const hero = this._gameState.hero;
+    if (!hero) return;
+    const nowMs = Date.now();
+    const expMs = Number.isFinite(expiresAtMs)
+      ? (expiresAtMs as number)
+      : nowMs + Math.max(0, durationMs);
+    const remainingMs = Math.max(0, expMs - nowMs);
+
+    const next: ActiveDebuff = {
+      type,
+      remainingMs,
+      durationMs: Math.max(0, durationMs),
+      expiresAtMs: expMs,
+    };
+
+    const debuffs = hero.debuffs
+      .filter((d) => d.type !== type)
+      .filter((d) => {
+        const exp = d.expiresAtMs ?? nowMs + d.remainingMs;
+        return exp > nowMs && d.remainingMs > 0;
+      });
+
+    debuffs.push(next);
+    this._gameState = {
+      ...this._gameState,
+      hero: { ...hero, debuffs },
+    };
+    this._notifyStateChange();
+  }
+
   /** Apply a full server state override (used for backward compat). */
   applyServerState(state: GameState): void {
     this._gameState = {

frontend/src/game/types.ts

@@ -30,6 +30,7 @@ export enum DebuffType {
   Stun = 'stun',       // no attacks (2 sec)
   Slow = 'slow',       // -40% movement
   Weaken = 'weaken',   // -30% outgoing damage
+  IceSlow = 'ice_slow', // -20% attack speed (Ice Guardian)
 }
 
 export interface BuffChargeState {
@@ -494,6 +495,13 @@ export interface BuffAppliedPayload {
   magnitude?: number;
 }
 
+export interface DebuffAppliedPayload {
+  debuffType: string;
+  durationMs?: number;
+  magnitude?: number;
+  expiresAt?: string;
+}
+
 export interface TownEnterPayload {
   townId: number;
   townName: string;

frontend/src/game/ws-handler.ts

@@ -25,8 +25,10 @@ import type {
   EnemyState,
   LootDrop,
   MerchantLootPayload,
+  DebuffAppliedPayload,
 } from './types';
-import { EnemyType, Rarity } from './types';
+import { DebuffType, EnemyType, Rarity } from './types';
+import { DEBUFF_DURATION_DEFAULTS } from '../shared/constants';
 
 // ---- Callback types for UI layer (App.tsx) ----
 
@@ -64,6 +66,9 @@ export function wireWSHandler(
   engine: GameEngine,
   callbacks: WSHandlerCallbacks,
 ): void {
+  const isDebuffType = (value: string): value is DebuffType => (
+    Object.values(DebuffType).includes(value as DebuffType)
+  );
   // ---- Server -> Client: Movement ----
 
   ws.on('hero_move', (msg: ServerMessage) => {
@@ -111,6 +116,16 @@ export function wireWSHandler(
     engine.applyAttack(p.source, p.damage, p.isCrit, p.heroHp, p.enemyHp);
   });
 
+  ws.on('debuff_applied', (msg: ServerMessage) => {
+    const p = msg.payload as DebuffAppliedPayload;
+    if (!p?.debuffType || !isDebuffType(p.debuffType)) return;
+    const nowMs = Date.now();
+    const fallbackMs = DEBUFF_DURATION_DEFAULTS[p.debuffType] ?? 0;
+    const durationMs = Number.isFinite(p.durationMs) ? Math.max(0, p.durationMs as number) : fallbackMs;
+    const expiresAtMs = p.expiresAt ? Date.parse(p.expiresAt) : nowMs + durationMs;
+    engine.applyDebuffApplied(p.debuffType, durationMs, expiresAtMs);
+  });
+
   ws.on('combat_end', (msg: ServerMessage) => {
     const p = msg.payload as CombatEndPayload;
     engine.applyCombatEnd();

frontend/src/i18n/en.ts

@@ -87,6 +87,7 @@ export const en = {
   debuffStun: 'Stun',
   debuffSlow: 'Slow',
   debuffWeaken: 'Weaken',
+  debuffIceSlow: 'Ice Slow',
 
   // Quest system
   questLog: 'Quest Log',

frontend/src/i18n/ru.ts

@@ -89,6 +89,7 @@ export const ru: Translations = {
   debuffStun: '\u041e\u0433\u043b\u0443\u0448\u0435\u043d\u0438\u0435',
   debuffSlow: '\u0417\u0430\u043c\u0435\u0434\u043b\u0435\u043d\u0438\u0435',
   debuffWeaken: '\u041e\u0441\u043b\u0430\u0431\u043b\u0435\u043d\u0438\u0435',
+  debuffIceSlow: '\u041b\u0435\u0434\u044f\u043d\u043e\u0435 \u0437\u0430\u043c\u0435\u0434\u043b\u0435\u043d\u0438\u0435',
 
   // Quest system
   questLog: '\u0416\u0443\u0440\u043d\u0430\u043b \u0437\u0430\u0434\u0430\u043d\u0438\u0439',

frontend/src/shared/constants.ts

@@ -96,6 +96,7 @@ export const DEBUFF_COLORS: Record<string, string> = {
   stun: '#ffdd44',
   slow: '#4488ff',
   weaken: '#aa44dd',
+  ice_slow: '#66aaff',
 };
 
 // ---- Debuff Default Durations (ms) ----
@@ -107,6 +108,7 @@ export const DEBUFF_DURATION_DEFAULTS: Record<string, number> = {
   stun: 2000,
   slow: 4000,
   weaken: 5000,
+  ice_slow: 4000,
 };
 
 /** Loot popup display duration in milliseconds */

frontend/src/ui/DebuffBar.tsx

@@ -11,6 +11,7 @@ const DEBUFF_META: Record<DebuffType, { icon: string; label: string }> = {
   [DebuffType.Stun]:   { icon: '\uD83D\uDCAB', label: 'Stun' },
   [DebuffType.Slow]:   { icon: '\uD83D\uDC22', label: 'Slow' },
   [DebuffType.Weaken]: { icon: '\uD83D\uDCC9', label: 'Weaken' },
+  [DebuffType.IceSlow]: { icon: '\u2744\uFE0F', label: 'Ice Slow' },
 };
 
 // ---- Types ----

frontend/src/ui/HeroPanel.tsx

@@ -27,6 +27,7 @@ function debuffLabel(tr: Translations, type: DebuffType): string {
     [DebuffType.Stun]: tr.debuffStun,
     [DebuffType.Slow]: tr.debuffSlow,
     [DebuffType.Weaken]: tr.debuffWeaken,
+    [DebuffType.IceSlow]: tr.debuffIceSlow,
   };
   return map[type] ?? type;
 }
@@ -130,7 +131,8 @@ export function HeroStatsContent({ hero, nowMs }: HeroPanelProps) {
     || hasActiveBuff(hero.activeBuffs, BuffType.PowerPotion, nowMs);
   const atkNerfed = hasActiveDebuff(hero.debuffs, DebuffType.Weaken, nowMs);
   const spdBuffed = hasActiveBuff(hero.activeBuffs, BuffType.WarCry, nowMs);
-  const spdNerfed = hasActiveDebuff(hero.debuffs, DebuffType.Freeze, nowMs);
+  const spdNerfed = hasActiveDebuff(hero.debuffs, DebuffType.Freeze, nowMs)
+    || hasActiveDebuff(hero.debuffs, DebuffType.IceSlow, nowMs);
   const defBuffed = hasActiveBuff(hero.activeBuffs, BuffType.Shield, nowMs);
 
   return (