diff --git a/client/src/App.tsx b/client/src/App.tsx
index 49e954d..d6cf4c4 100644
--- a/client/src/App.tsx
+++ b/client/src/App.tsx
@@ -5,6 +5,7 @@ import { LoginPage, RegisterPage, useAuthStore } from '@/features/auth';
 import { CampaignsPage, CampaignDetailPage } from '@/features/campaigns';
 import { CharacterSheetPage } from '@/features/characters';
 import { BattlePage } from '@/features/battle';
+import { LibraryPage } from '@/features/library';
 import { ProtectedRoute } from '@/shared/components/protected-route';
 import { Layout } from '@/shared/components/layout';
 
@@ -48,7 +49,7 @@ function AppContent() {
           <Route path="/campaigns/:id" element={<CampaignDetailPage />} />
           <Route path="/campaigns/:id/characters/:characterId" element={<CharacterSheetPage />} />
           <Route path="/campaigns/:id/battle" element={<BattlePage />} />
-          <Route path="/library" element={<div>Library (TODO)</div>} />
+          <Route path="/campaigns/:id/library" element={<LibraryPage />} />
         </Route>
       </Route>
 
diff --git a/client/src/features/campaigns/components/campaign-detail-page.tsx b/client/src/features/campaigns/components/campaign-detail-page.tsx
index bfeee1e..237d77a 100644
--- a/client/src/features/campaigns/components/campaign-detail-page.tsx
+++ b/client/src/features/campaigns/components/campaign-detail-page.tsx
@@ -10,7 +10,8 @@ import {
   Crown,
   Shield,
   Heart,
-  FileJson
+  FileJson,
+  Library
 } from 'lucide-react';
 import {
   Button,
@@ -268,7 +269,7 @@ export function CampaignDetailPage() {
       </div>
 
       {/* Quick Actions */}
-      <div className="grid grid-cols-1 sm:grid-cols-3 gap-3">
+      <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-4 gap-3">
         <Card className="p-4 hover:border-border-hover cursor-pointer transition-colors active:scale-[0.98]" onClick={() => navigate(`/campaigns/${id}/battle`)}>
           <div className="flex items-center gap-3">
             <div className="h-10 w-10 rounded-lg bg-red-500/20 flex items-center justify-center flex-shrink-0">
@@ -280,6 +281,19 @@ export function CampaignDetailPage() {
             </div>
           </div>
         </Card>
+        {canManage && (
+          <Card className="p-4 hover:border-border-hover cursor-pointer transition-colors active:scale-[0.98]" onClick={() => navigate(`/campaigns/${id}/library`)}>
+            <div className="flex items-center gap-3">
+              <div className="h-10 w-10 rounded-lg bg-purple-500/20 flex items-center justify-center flex-shrink-0">
+                <Library className="h-5 w-5 text-purple-500" />
+              </div>
+              <div className="min-w-0">
+                <p className="font-medium text-text-primary">Bibliothek</p>
+                <p className="text-sm text-text-secondary">Karten & NPCs</p>
+              </div>
+            </div>
+          </Card>
+        )}
         <Card className="p-4 hover:border-border-hover cursor-pointer transition-colors opacity-50">
           <div className="flex items-center gap-3">
             <div className="h-10 w-10 rounded-lg bg-blue-500/20 flex items-center justify-center flex-shrink-0">
diff --git a/client/src/features/library/components/create-combatant-modal.tsx b/client/src/features/library/components/create-combatant-modal.tsx
new file mode 100644
index 0000000..c22ca9d
--- /dev/null
+++ b/client/src/features/library/components/create-combatant-modal.tsx
@@ -0,0 +1,390 @@
+import { useState } from 'react';
+import { X, Plus, Trash2 } from 'lucide-react';
+import { cn } from '@/shared/lib/utils';
+
+interface CombatantAbility {
+  name: string;
+  actionCost: number;
+  actionType: 'ACTION' | 'REACTION' | 'FREE';
+  description: string;
+  damage?: string;
+  traits?: string[];
+}
+
+interface CreateCombatantModalProps {
+  onClose: () => void;
+  onCreate: (data: {
+    name: string;
+    type: 'NPC' | 'MONSTER';
+    level: number;
+    hpMax: number;
+    ac: number;
+    fortitude: number;
+    reflex: number;
+    will: number;
+    perception: number;
+    speed: number;
+    description?: string;
+    abilities: CombatantAbility[];
+  }) => void;
+  isLoading?: boolean;
+}
+
+export function CreateCombatantModal({ onClose, onCreate, isLoading }: CreateCombatantModalProps) {
+  const [name, setName] = useState('');
+  const [type, setType] = useState<'NPC' | 'MONSTER'>('NPC');
+  const [level, setLevel] = useState(1);
+  const [hpMax, setHpMax] = useState(20);
+  const [ac, setAc] = useState(15);
+  const [fortitude, setFortitude] = useState(5);
+  const [reflex, setReflex] = useState(5);
+  const [will, setWill] = useState(5);
+  const [perception, setPerception] = useState(5);
+  const [speed, setSpeed] = useState(25);
+  const [description, setDescription] = useState('');
+  const [abilities, setAbilities] = useState<CombatantAbility[]>([]);
+  const [showAddAbility, setShowAddAbility] = useState(false);
+
+  // Ability form state
+  const [abilityName, setAbilityName] = useState('');
+  const [abilityActionCost, setAbilityActionCost] = useState(1);
+  const [abilityActionType, setAbilityActionType] = useState<'ACTION' | 'REACTION' | 'FREE'>('ACTION');
+  const [abilityDescription, setAbilityDescription] = useState('');
+  const [abilityDamage, setAbilityDamage] = useState('');
+
+  const handleAddAbility = () => {
+    if (!abilityName.trim() || !abilityDescription.trim()) return;
+
+    setAbilities([
+      ...abilities,
+      {
+        name: abilityName.trim(),
+        actionCost: abilityActionCost,
+        actionType: abilityActionType,
+        description: abilityDescription.trim(),
+        damage: abilityDamage.trim() || undefined,
+      },
+    ]);
+
+    // Reset ability form
+    setAbilityName('');
+    setAbilityActionCost(1);
+    setAbilityActionType('ACTION');
+    setAbilityDescription('');
+    setAbilityDamage('');
+    setShowAddAbility(false);
+  };
+
+  const handleRemoveAbility = (index: number) => {
+    setAbilities(abilities.filter((_, i) => i !== index));
+  };
+
+  const handleSubmit = (e: React.FormEvent) => {
+    e.preventDefault();
+    if (!name.trim()) return;
+
+    onCreate({
+      name: name.trim(),
+      type,
+      level,
+      hpMax,
+      ac,
+      fortitude,
+      reflex,
+      will,
+      perception,
+      speed,
+      description: description.trim() || undefined,
+      abilities,
+    });
+  };
+
+  return (
+    <div className="fixed inset-0 z-50 flex items-center justify-center p-4 bg-black/70">
+      <div className="bg-bg-secondary border border-border-default rounded-xl w-full max-w-2xl max-h-[90vh] overflow-y-auto">
+        {/* Header */}
+        <div className="flex items-center justify-between p-4 border-b border-border-default sticky top-0 bg-bg-secondary z-10">
+          <h2 className="text-lg font-semibold text-text-primary">NPC/Monster erstellen</h2>
+          <button
+            onClick={onClose}
+            className="p-1 rounded-lg hover:bg-white/10 text-text-secondary transition-colors"
+          >
+            <X className="w-5 h-5" />
+          </button>
+        </div>
+
+        {/* Form */}
+        <form onSubmit={handleSubmit} className="p-4 space-y-4">
+          {/* Basic Info */}
+          <div className="grid grid-cols-2 gap-4">
+            <div className="col-span-2 sm:col-span-1">
+              <label className="block text-sm font-medium text-text-secondary mb-2">Name</label>
+              <input
+                type="text"
+                value={name}
+                onChange={(e) => setName(e.target.value)}
+                placeholder="z.B. Goblin Krieger"
+                className="w-full px-3 py-2 bg-bg-tertiary border border-border-default rounded-lg text-text-primary placeholder:text-text-secondary focus:outline-none focus:border-primary"
+                required
+              />
+            </div>
+            <div>
+              <label className="block text-sm font-medium text-text-secondary mb-2">Typ</label>
+              <select
+                value={type}
+                onChange={(e) => setType(e.target.value as 'NPC' | 'MONSTER')}
+                className="w-full px-3 py-2 bg-bg-tertiary border border-border-default rounded-lg text-text-primary focus:outline-none focus:border-primary"
+              >
+                <option value="NPC">NPC</option>
+                <option value="MONSTER">Monster</option>
+              </select>
+            </div>
+          </div>
+
+          {/* Stats Row 1 */}
+          <div className="grid grid-cols-3 gap-4">
+            <div>
+              <label className="block text-sm font-medium text-text-secondary mb-2">Level</label>
+              <input
+                type="number"
+                value={level}
+                onChange={(e) => setLevel(parseInt(e.target.value) || 0)}
+                min={-1}
+                max={30}
+                className="w-full px-3 py-2 bg-bg-tertiary border border-border-default rounded-lg text-text-primary focus:outline-none focus:border-primary"
+              />
+            </div>
+            <div>
+              <label className="block text-sm font-medium text-text-secondary mb-2">HP</label>
+              <input
+                type="number"
+                value={hpMax}
+                onChange={(e) => setHpMax(parseInt(e.target.value) || 1)}
+                min={1}
+                className="w-full px-3 py-2 bg-bg-tertiary border border-border-default rounded-lg text-text-primary focus:outline-none focus:border-primary"
+              />
+            </div>
+            <div>
+              <label className="block text-sm font-medium text-text-secondary mb-2">RK</label>
+              <input
+                type="number"
+                value={ac}
+                onChange={(e) => setAc(parseInt(e.target.value) || 0)}
+                min={0}
+                className="w-full px-3 py-2 bg-bg-tertiary border border-border-default rounded-lg text-text-primary focus:outline-none focus:border-primary"
+              />
+            </div>
+          </div>
+
+          {/* Saves */}
+          <div className="grid grid-cols-3 gap-4">
+            <div>
+              <label className="block text-sm font-medium text-text-secondary mb-2">Zähigkeit</label>
+              <input
+                type="number"
+                value={fortitude}
+                onChange={(e) => setFortitude(parseInt(e.target.value) || 0)}
+                className="w-full px-3 py-2 bg-bg-tertiary border border-border-default rounded-lg text-text-primary focus:outline-none focus:border-primary"
+              />
+            </div>
+            <div>
+              <label className="block text-sm font-medium text-text-secondary mb-2">Reflex</label>
+              <input
+                type="number"
+                value={reflex}
+                onChange={(e) => setReflex(parseInt(e.target.value) || 0)}
+                className="w-full px-3 py-2 bg-bg-tertiary border border-border-default rounded-lg text-text-primary focus:outline-none focus:border-primary"
+              />
+            </div>
+            <div>
+              <label className="block text-sm font-medium text-text-secondary mb-2">Wille</label>
+              <input
+                type="number"
+                value={will}
+                onChange={(e) => setWill(parseInt(e.target.value) || 0)}
+                className="w-full px-3 py-2 bg-bg-tertiary border border-border-default rounded-lg text-text-primary focus:outline-none focus:border-primary"
+              />
+            </div>
+          </div>
+
+          {/* Perception & Speed */}
+          <div className="grid grid-cols-2 gap-4">
+            <div>
+              <label className="block text-sm font-medium text-text-secondary mb-2">Wahrnehmung</label>
+              <input
+                type="number"
+                value={perception}
+                onChange={(e) => setPerception(parseInt(e.target.value) || 0)}
+                className="w-full px-3 py-2 bg-bg-tertiary border border-border-default rounded-lg text-text-primary focus:outline-none focus:border-primary"
+              />
+            </div>
+            <div>
+              <label className="block text-sm font-medium text-text-secondary mb-2">Geschwindigkeit (ft)</label>
+              <input
+                type="number"
+                value={speed}
+                onChange={(e) => setSpeed(parseInt(e.target.value) || 0)}
+                min={0}
+                step={5}
+                className="w-full px-3 py-2 bg-bg-tertiary border border-border-default rounded-lg text-text-primary focus:outline-none focus:border-primary"
+              />
+            </div>
+          </div>
+
+          {/* Description */}
+          <div>
+            <label className="block text-sm font-medium text-text-secondary mb-2">Beschreibung (optional)</label>
+            <textarea
+              value={description}
+              onChange={(e) => setDescription(e.target.value)}
+              placeholder="Notizen, Taktiken, besondere Merkmale..."
+              rows={2}
+              className="w-full px-3 py-2 bg-bg-tertiary border border-border-default rounded-lg text-text-primary placeholder:text-text-secondary focus:outline-none focus:border-primary resize-none"
+            />
+          </div>
+
+          {/* Abilities */}
+          <div>
+            <div className="flex items-center justify-between mb-2">
+              <label className="text-sm font-medium text-text-secondary">Fähigkeiten</label>
+              <button
+                type="button"
+                onClick={() => setShowAddAbility(!showAddAbility)}
+                className="text-sm text-primary hover:text-primary/80 flex items-center gap-1"
+              >
+                <Plus className="w-4 h-4" />
+                Hinzufügen
+              </button>
+            </div>
+
+            {/* Add Ability Form */}
+            {showAddAbility && (
+              <div className="p-3 bg-bg-tertiary rounded-lg space-y-3 mb-3">
+                <div className="grid grid-cols-2 gap-3">
+                  <input
+                    type="text"
+                    value={abilityName}
+                    onChange={(e) => setAbilityName(e.target.value)}
+                    placeholder="Name (z.B. Schwerthieb)"
+                    className="px-3 py-2 bg-bg-secondary border border-border-default rounded-lg text-text-primary text-sm focus:outline-none focus:border-primary"
+                  />
+                  <div className="flex gap-2">
+                    <select
+                      value={abilityActionCost}
+                      onChange={(e) => setAbilityActionCost(parseInt(e.target.value))}
+                      className="flex-1 px-2 py-2 bg-bg-secondary border border-border-default rounded-lg text-text-primary text-sm focus:outline-none focus:border-primary"
+                    >
+                      <option value={0}>0</option>
+                      <option value={1}>1</option>
+                      <option value={2}>2</option>
+                      <option value={3}>3</option>
+                    </select>
+                    <select
+                      value={abilityActionType}
+                      onChange={(e) => setAbilityActionType(e.target.value as 'ACTION' | 'REACTION' | 'FREE')}
+                      className="flex-1 px-2 py-2 bg-bg-secondary border border-border-default rounded-lg text-text-primary text-sm focus:outline-none focus:border-primary"
+                    >
+                      <option value="ACTION">Aktion</option>
+                      <option value="REACTION">Reaktion</option>
+                      <option value="FREE">Frei</option>
+                    </select>
+                  </div>
+                </div>
+                <input
+                  type="text"
+                  value={abilityDamage}
+                  onChange={(e) => setAbilityDamage(e.target.value)}
+                  placeholder="Schaden (z.B. 1d8+4 Hieb)"
+                  className="w-full px-3 py-2 bg-bg-secondary border border-border-default rounded-lg text-text-primary text-sm focus:outline-none focus:border-primary"
+                />
+                <textarea
+                  value={abilityDescription}
+                  onChange={(e) => setAbilityDescription(e.target.value)}
+                  placeholder="Beschreibung..."
+                  rows={2}
+                  className="w-full px-3 py-2 bg-bg-secondary border border-border-default rounded-lg text-text-primary text-sm focus:outline-none focus:border-primary resize-none"
+                />
+                <div className="flex gap-2">
+                  <button
+                    type="button"
+                    onClick={() => setShowAddAbility(false)}
+                    className="flex-1 px-3 py-1.5 bg-bg-secondary text-text-secondary rounded-lg text-sm hover:bg-white/10"
+                  >
+                    Abbrechen
+                  </button>
+                  <button
+                    type="button"
+                    onClick={handleAddAbility}
+                    disabled={!abilityName.trim() || !abilityDescription.trim()}
+                    className="flex-1 px-3 py-1.5 bg-primary text-white rounded-lg text-sm hover:bg-primary/80 disabled:opacity-50"
+                  >
+                    Hinzufügen
+                  </button>
+                </div>
+              </div>
+            )}
+
+            {/* Ability List */}
+            {abilities.length > 0 ? (
+              <div className="space-y-2">
+                {abilities.map((ability, index) => (
+                  <div
+                    key={index}
+                    className="flex items-start justify-between gap-2 p-2 bg-bg-tertiary rounded-lg"
+                  >
+                    <div className="flex-1 min-w-0">
+                      <div className="flex items-center gap-2">
+                        <span className="font-medium text-text-primary text-sm">{ability.name}</span>
+                        <span className="text-xs px-1.5 py-0.5 bg-primary/20 text-primary rounded">
+                          {ability.actionCost > 0 ? `${ability.actionCost} Aktion${ability.actionCost > 1 ? 'en' : ''}` : ability.actionType === 'REACTION' ? 'Reaktion' : 'Frei'}
+                        </span>
+                      </div>
+                      {ability.damage && (
+                        <p className="text-xs text-red-400 mt-0.5">{ability.damage}</p>
+                      )}
+                      <p className="text-xs text-text-secondary mt-0.5 line-clamp-2">{ability.description}</p>
+                    </div>
+                    <button
+                      type="button"
+                      onClick={() => handleRemoveAbility(index)}
+                      className="p-1 text-text-secondary hover:text-red-400"
+                    >
+                      <Trash2 className="w-4 h-4" />
+                    </button>
+                  </div>
+                ))}
+              </div>
+            ) : (
+              <p className="text-sm text-text-secondary text-center py-4 bg-bg-tertiary rounded-lg">
+                Keine Fähigkeiten hinzugefügt
+              </p>
+            )}
+          </div>
+
+          {/* Actions */}
+          <div className="flex gap-3 pt-2">
+            <button
+              type="button"
+              onClick={onClose}
+              className="flex-1 px-4 py-2 bg-bg-tertiary text-text-primary rounded-lg hover:bg-white/10 transition-colors"
+            >
+              Abbrechen
+            </button>
+            <button
+              type="submit"
+              disabled={!name.trim() || isLoading}
+              className={cn(
+                'flex-1 px-4 py-2 rounded-lg font-medium transition-colors',
+                name.trim() && !isLoading
+                  ? 'bg-primary text-white hover:bg-primary/80'
+                  : 'bg-primary/50 text-white/50 cursor-not-allowed'
+              )}
+            >
+              {isLoading ? 'Erstellen...' : 'Erstellen'}
+            </button>
+          </div>
+        </form>
+      </div>
+    </div>
+  );
+}
diff --git a/client/src/features/library/components/library-page.tsx b/client/src/features/library/components/library-page.tsx
new file mode 100644
index 0000000..1a58713
--- /dev/null
+++ b/client/src/features/library/components/library-page.tsx
@@ -0,0 +1,324 @@
+import { useState } from 'react';
+import { useParams, useNavigate } from 'react-router-dom';
+import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
+import { ArrowLeft, Map, Users, Plus, Trash2, Image, Swords } from 'lucide-react';
+import { api } from '@/shared/lib/api';
+import { useAuthStore } from '@/features/auth';
+import { UploadMapModal } from './upload-map-modal';
+import { CreateCombatantModal } from './create-combatant-modal';
+import type { BattleMap, Combatant } from '@/shared/types';
+import { cn } from '@/shared/lib/utils';
+
+type Tab = 'maps' | 'combatants';
+
+const API_URL = import.meta.env.VITE_API_URL?.replace('/api', '') || 'http://localhost:5000';
+
+export function LibraryPage() {
+  const { id: campaignId } = useParams<{ id: string }>();
+  const navigate = useNavigate();
+  const queryClient = useQueryClient();
+  const { user } = useAuthStore();
+
+  const [activeTab, setActiveTab] = useState<Tab>('maps');
+  const [showUploadMap, setShowUploadMap] = useState(false);
+  const [showCreateCombatant, setShowCreateCombatant] = useState(false);
+
+  // Fetch campaign to check GM status
+  const { data: campaign } = useQuery({
+    queryKey: ['campaign', campaignId],
+    queryFn: () => api.getCampaign(campaignId!),
+    enabled: !!campaignId,
+  });
+
+  const isGM = campaign?.gmId === user?.id;
+
+  // Redirect non-GMs
+  if (campaign && !isGM) {
+    navigate(`/campaigns/${campaignId}`);
+    return null;
+  }
+
+  // Fetch battle maps
+  const { data: maps = [], isLoading: mapsLoading } = useQuery({
+    queryKey: ['battleMaps', campaignId],
+    queryFn: () => api.getBattleMaps(campaignId!),
+    enabled: !!campaignId,
+  });
+
+  // Fetch combatants
+  const { data: combatants = [], isLoading: combatantsLoading } = useQuery({
+    queryKey: ['combatants', campaignId],
+    queryFn: () => api.getCombatants(campaignId!),
+    enabled: !!campaignId,
+  });
+
+  // Upload map mutation
+  const uploadMapMutation = useMutation({
+    mutationFn: (data: Parameters<typeof api.uploadBattleMap>[1]) =>
+      api.uploadBattleMap(campaignId!, data),
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ['battleMaps', campaignId] });
+      setShowUploadMap(false);
+    },
+  });
+
+  // Delete map mutation
+  const deleteMapMutation = useMutation({
+    mutationFn: (mapId: string) => api.deleteBattleMap(campaignId!, mapId),
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ['battleMaps', campaignId] });
+    },
+  });
+
+  // Create combatant mutation
+  const createCombatantMutation = useMutation({
+    mutationFn: (data: Parameters<typeof api.createCombatant>[1]) =>
+      api.createCombatant(campaignId!, data),
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ['combatants', campaignId] });
+      setShowCreateCombatant(false);
+    },
+  });
+
+  // Delete combatant mutation
+  const deleteCombatantMutation = useMutation({
+    mutationFn: (combatantId: string) => api.deleteCombatant(campaignId!, combatantId),
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ['combatants', campaignId] });
+    },
+  });
+
+  return (
+    <div className="min-h-screen bg-bg-primary">
+      {/* Header */}
+      <header className="sticky top-0 z-10 bg-bg-secondary border-b border-border-default">
+        <div className="max-w-6xl mx-auto px-4 py-3">
+          <div className="flex items-center gap-3">
+            <button
+              onClick={() => navigate(`/campaigns/${campaignId}`)}
+              className="p-2 rounded-lg hover:bg-white/10 text-text-secondary transition-colors"
+            >
+              <ArrowLeft className="w-5 h-5" />
+            </button>
+            <div>
+              <h1 className="text-lg font-semibold text-text-primary">Bibliothek</h1>
+              <p className="text-sm text-text-secondary">{campaign?.name}</p>
+            </div>
+          </div>
+        </div>
+
+        {/* Tabs */}
+        <div className="max-w-6xl mx-auto px-4">
+          <div className="flex gap-1">
+            <button
+              onClick={() => setActiveTab('maps')}
+              className={cn(
+                'flex items-center gap-2 px-4 py-2 text-sm font-medium border-b-2 transition-colors',
+                activeTab === 'maps'
+                  ? 'border-primary text-primary'
+                  : 'border-transparent text-text-secondary hover:text-text-primary'
+              )}
+            >
+              <Map className="w-4 h-4" />
+              Karten ({maps.length})
+            </button>
+            <button
+              onClick={() => setActiveTab('combatants')}
+              className={cn(
+                'flex items-center gap-2 px-4 py-2 text-sm font-medium border-b-2 transition-colors',
+                activeTab === 'combatants'
+                  ? 'border-primary text-primary'
+                  : 'border-transparent text-text-secondary hover:text-text-primary'
+              )}
+            >
+              <Users className="w-4 h-4" />
+              NPCs ({combatants.length})
+            </button>
+          </div>
+        </div>
+      </header>
+
+      {/* Content */}
+      <main className="max-w-6xl mx-auto px-4 py-6">
+        {activeTab === 'maps' ? (
+          <div>
+            {/* Add Map Button */}
+            <div className="flex justify-end mb-4">
+              <button
+                onClick={() => setShowUploadMap(true)}
+                className="flex items-center gap-2 px-4 py-2 bg-primary text-white rounded-lg hover:bg-primary/80 transition-colors"
+              >
+                <Plus className="w-4 h-4" />
+                Karte hochladen
+              </button>
+            </div>
+
+            {/* Maps Grid */}
+            {mapsLoading ? (
+              <div className="text-center py-12 text-text-secondary">Laden...</div>
+            ) : maps.length === 0 ? (
+              <div className="text-center py-12">
+                <Image className="w-12 h-12 text-text-secondary mx-auto mb-3" />
+                <p className="text-text-secondary">Noch keine Karten hochgeladen</p>
+                <button
+                  onClick={() => setShowUploadMap(true)}
+                  className="mt-4 text-primary hover:text-primary/80"
+                >
+                  Erste Karte hochladen
+                </button>
+              </div>
+            ) : (
+              <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 gap-4">
+                {maps.map((map: BattleMap) => (
+                  <div
+                    key={map.id}
+                    className="bg-bg-secondary border border-border-default rounded-lg overflow-hidden group"
+                  >
+                    {/* Map Preview */}
+                    <div className="aspect-video bg-black/30 relative">
+                      <img
+                        src={`${API_URL}${map.imageUrl}`}
+                        alt={map.name}
+                        className="w-full h-full object-cover"
+                      />
+                      {/* Overlay with actions */}
+                      <div className="absolute inset-0 bg-black/60 opacity-0 group-hover:opacity-100 transition-opacity flex items-center justify-center gap-2">
+                        <button
+                          onClick={() => {
+                            if (confirm('Karte wirklich löschen?')) {
+                              deleteMapMutation.mutate(map.id);
+                            }
+                          }}
+                          className="p-2 bg-red-500/20 text-red-400 rounded-lg hover:bg-red-500/30"
+                        >
+                          <Trash2 className="w-5 h-5" />
+                        </button>
+                      </div>
+                    </div>
+                    {/* Map Info */}
+                    <div className="p-3">
+                      <h3 className="font-medium text-text-primary truncate">{map.name}</h3>
+                      <p className="text-sm text-text-secondary">
+                        {map.gridSizeX} x {map.gridSizeY} Grid
+                      </p>
+                    </div>
+                  </div>
+                ))}
+              </div>
+            )}
+          </div>
+        ) : (
+          <div>
+            {/* Add Combatant Button */}
+            <div className="flex justify-end mb-4">
+              <button
+                onClick={() => setShowCreateCombatant(true)}
+                className="flex items-center gap-2 px-4 py-2 bg-primary text-white rounded-lg hover:bg-primary/80 transition-colors"
+              >
+                <Plus className="w-4 h-4" />
+                NPC erstellen
+              </button>
+            </div>
+
+            {/* Combatants List */}
+            {combatantsLoading ? (
+              <div className="text-center py-12 text-text-secondary">Laden...</div>
+            ) : combatants.length === 0 ? (
+              <div className="text-center py-12">
+                <Swords className="w-12 h-12 text-text-secondary mx-auto mb-3" />
+                <p className="text-text-secondary">Noch keine NPCs erstellt</p>
+                <button
+                  onClick={() => setShowCreateCombatant(true)}
+                  className="mt-4 text-primary hover:text-primary/80"
+                >
+                  Ersten NPC erstellen
+                </button>
+              </div>
+            ) : (
+              <div className="space-y-2">
+                {combatants.map((combatant: Combatant) => (
+                  <div
+                    key={combatant.id}
+                    className="bg-bg-secondary border border-border-default rounded-lg p-4 flex items-center justify-between gap-4"
+                  >
+                    <div className="flex items-center gap-4 min-w-0 flex-1">
+                      {/* Avatar */}
+                      <div className={cn(
+                        'w-12 h-12 rounded-lg flex items-center justify-center flex-shrink-0',
+                        combatant.type === 'MONSTER' ? 'bg-red-500/20' : 'bg-blue-500/20'
+                      )}>
+                        <Swords className={cn(
+                          'w-6 h-6',
+                          combatant.type === 'MONSTER' ? 'text-red-400' : 'text-blue-400'
+                        )} />
+                      </div>
+
+                      {/* Info */}
+                      <div className="min-w-0 flex-1">
+                        <div className="flex items-center gap-2">
+                          <h3 className="font-medium text-text-primary truncate">{combatant.name}</h3>
+                          <span className={cn(
+                            'text-xs px-1.5 py-0.5 rounded',
+                            combatant.type === 'MONSTER'
+                              ? 'bg-red-500/20 text-red-400'
+                              : 'bg-blue-500/20 text-blue-400'
+                          )}>
+                            {combatant.type === 'MONSTER' ? 'Monster' : 'NPC'}
+                          </span>
+                        </div>
+                        <div className="flex items-center gap-4 text-sm text-text-secondary mt-1">
+                          <span>Lvl {combatant.level}</span>
+                          <span>HP {combatant.hpMax}</span>
+                          <span>RK {combatant.ac}</span>
+                          <span className="hidden sm:inline">
+                            Rett: +{combatant.fortitude}/+{combatant.reflex}/+{combatant.will}
+                          </span>
+                        </div>
+                        {combatant.abilities && combatant.abilities.length > 0 && (
+                          <p className="text-xs text-text-secondary mt-1">
+                            {combatant.abilities.length} Fähigkeit{combatant.abilities.length > 1 ? 'en' : ''}
+                          </p>
+                        )}
+                      </div>
+                    </div>
+
+                    {/* Actions */}
+                    <div className="flex items-center gap-2 flex-shrink-0">
+                      <button
+                        onClick={() => {
+                          if (confirm('NPC wirklich löschen?')) {
+                            deleteCombatantMutation.mutate(combatant.id);
+                          }
+                        }}
+                        className="p-2 text-text-secondary hover:text-red-400 transition-colors"
+                      >
+                        <Trash2 className="w-5 h-5" />
+                      </button>
+                    </div>
+                  </div>
+                ))}
+              </div>
+            )}
+          </div>
+        )}
+      </main>
+
+      {/* Modals */}
+      {showUploadMap && (
+        <UploadMapModal
+          onClose={() => setShowUploadMap(false)}
+          onUpload={(data) => uploadMapMutation.mutate(data)}
+          isLoading={uploadMapMutation.isPending}
+        />
+      )}
+
+      {showCreateCombatant && (
+        <CreateCombatantModal
+          onClose={() => setShowCreateCombatant(false)}
+          onCreate={(data) => createCombatantMutation.mutate(data)}
+          isLoading={createCombatantMutation.isPending}
+        />
+      )}
+    </div>
+  );
+}
diff --git a/client/src/features/library/components/upload-map-modal.tsx b/client/src/features/library/components/upload-map-modal.tsx
new file mode 100644
index 0000000..47ecb47
--- /dev/null
+++ b/client/src/features/library/components/upload-map-modal.tsx
@@ -0,0 +1,231 @@
+import { useState, useRef } from 'react';
+import { X, Upload, Image } from 'lucide-react';
+import { cn } from '@/shared/lib/utils';
+
+interface UploadMapModalProps {
+  onClose: () => void;
+  onUpload: (data: {
+    name: string;
+    gridSizeX: number;
+    gridSizeY: number;
+    gridOffsetX: number;
+    gridOffsetY: number;
+    image: File;
+  }) => void;
+  isLoading?: boolean;
+}
+
+export function UploadMapModal({ onClose, onUpload, isLoading }: UploadMapModalProps) {
+  const [name, setName] = useState('');
+  const [gridSizeX, setGridSizeX] = useState(20);
+  const [gridSizeY, setGridSizeY] = useState(20);
+  const [gridOffsetX, setGridOffsetX] = useState(0);
+  const [gridOffsetY, setGridOffsetY] = useState(0);
+  const [selectedFile, setSelectedFile] = useState<File | null>(null);
+  const [preview, setPreview] = useState<string | null>(null);
+  const fileInputRef = useRef<HTMLInputElement>(null);
+
+  const handleFileSelect = (e: React.ChangeEvent<HTMLInputElement>) => {
+    const file = e.target.files?.[0];
+    if (file) {
+      setSelectedFile(file);
+      const reader = new FileReader();
+      reader.onloadend = () => {
+        setPreview(reader.result as string);
+      };
+      reader.readAsDataURL(file);
+
+      // Auto-fill name from filename if empty
+      if (!name) {
+        setName(file.name.replace(/\.[^/.]+$/, ''));
+      }
+    }
+  };
+
+  const handleSubmit = (e: React.FormEvent) => {
+    e.preventDefault();
+    if (!selectedFile || !name.trim()) return;
+
+    onUpload({
+      name: name.trim(),
+      gridSizeX,
+      gridSizeY,
+      gridOffsetX,
+      gridOffsetY,
+      image: selectedFile,
+    });
+  };
+
+  return (
+    <div className="fixed inset-0 z-50 flex items-center justify-center p-4 bg-black/70">
+      <div className="bg-bg-secondary border border-border-default rounded-xl w-full max-w-lg max-h-[90vh] overflow-y-auto">
+        {/* Header */}
+        <div className="flex items-center justify-between p-4 border-b border-border-default">
+          <h2 className="text-lg font-semibold text-text-primary">Karte hochladen</h2>
+          <button
+            onClick={onClose}
+            className="p-1 rounded-lg hover:bg-white/10 text-text-secondary transition-colors"
+          >
+            <X className="w-5 h-5" />
+          </button>
+        </div>
+
+        {/* Form */}
+        <form onSubmit={handleSubmit} className="p-4 space-y-4">
+          {/* File Upload */}
+          <div>
+            <label className="block text-sm font-medium text-text-secondary mb-2">
+              Kartenbild
+            </label>
+            <input
+              ref={fileInputRef}
+              type="file"
+              accept="image/png,image/jpeg,image/webp"
+              onChange={handleFileSelect}
+              className="hidden"
+            />
+            {preview ? (
+              <div className="relative">
+                <img
+                  src={preview}
+                  alt="Preview"
+                  className="w-full h-48 object-contain bg-black/30 rounded-lg"
+                />
+                <button
+                  type="button"
+                  onClick={() => {
+                    setSelectedFile(null);
+                    setPreview(null);
+                  }}
+                  className="absolute top-2 right-2 p-1 rounded-full bg-black/50 hover:bg-black/70 text-white"
+                >
+                  <X className="w-4 h-4" />
+                </button>
+              </div>
+            ) : (
+              <button
+                type="button"
+                onClick={() => fileInputRef.current?.click()}
+                className="w-full h-48 border-2 border-dashed border-border-default rounded-lg flex flex-col items-center justify-center gap-2 hover:border-primary hover:bg-primary/5 transition-colors"
+              >
+                <Image className="w-8 h-8 text-text-secondary" />
+                <span className="text-sm text-text-secondary">Klicken zum Auswählen</span>
+                <span className="text-xs text-text-secondary">PNG, JPG, WebP (max. 10MB)</span>
+              </button>
+            )}
+          </div>
+
+          {/* Name */}
+          <div>
+            <label className="block text-sm font-medium text-text-secondary mb-2">
+              Name
+            </label>
+            <input
+              type="text"
+              value={name}
+              onChange={(e) => setName(e.target.value)}
+              placeholder="z.B. Taverne im Wald"
+              className="w-full px-3 py-2 bg-bg-tertiary border border-border-default rounded-lg text-text-primary placeholder:text-text-secondary focus:outline-none focus:border-primary"
+              required
+            />
+          </div>
+
+          {/* Grid Size */}
+          <div className="grid grid-cols-2 gap-4">
+            <div>
+              <label className="block text-sm font-medium text-text-secondary mb-2">
+                Grid Spalten (X)
+              </label>
+              <input
+                type="number"
+                value={gridSizeX}
+                onChange={(e) => setGridSizeX(parseInt(e.target.value) || 1)}
+                min={1}
+                max={100}
+                className="w-full px-3 py-2 bg-bg-tertiary border border-border-default rounded-lg text-text-primary focus:outline-none focus:border-primary"
+              />
+            </div>
+            <div>
+              <label className="block text-sm font-medium text-text-secondary mb-2">
+                Grid Reihen (Y)
+              </label>
+              <input
+                type="number"
+                value={gridSizeY}
+                onChange={(e) => setGridSizeY(parseInt(e.target.value) || 1)}
+                min={1}
+                max={100}
+                className="w-full px-3 py-2 bg-bg-tertiary border border-border-default rounded-lg text-text-primary focus:outline-none focus:border-primary"
+              />
+            </div>
+          </div>
+
+          {/* Grid Offset */}
+          <div className="grid grid-cols-2 gap-4">
+            <div>
+              <label className="block text-sm font-medium text-text-secondary mb-2">
+                Offset X (px)
+              </label>
+              <input
+                type="number"
+                value={gridOffsetX}
+                onChange={(e) => setGridOffsetX(parseInt(e.target.value) || 0)}
+                min={0}
+                className="w-full px-3 py-2 bg-bg-tertiary border border-border-default rounded-lg text-text-primary focus:outline-none focus:border-primary"
+              />
+            </div>
+            <div>
+              <label className="block text-sm font-medium text-text-secondary mb-2">
+                Offset Y (px)
+              </label>
+              <input
+                type="number"
+                value={gridOffsetY}
+                onChange={(e) => setGridOffsetY(parseInt(e.target.value) || 0)}
+                min={0}
+                className="w-full px-3 py-2 bg-bg-tertiary border border-border-default rounded-lg text-text-primary focus:outline-none focus:border-primary"
+              />
+            </div>
+          </div>
+
+          <p className="text-xs text-text-secondary">
+            Offset ist nützlich für Karten mit vorgezeichnetem Grid, um das digitale Grid auszurichten.
+          </p>
+
+          {/* Actions */}
+          <div className="flex gap-3 pt-2">
+            <button
+              type="button"
+              onClick={onClose}
+              className="flex-1 px-4 py-2 bg-bg-tertiary text-text-primary rounded-lg hover:bg-white/10 transition-colors"
+            >
+              Abbrechen
+            </button>
+            <button
+              type="submit"
+              disabled={!selectedFile || !name.trim() || isLoading}
+              className={cn(
+                'flex-1 px-4 py-2 rounded-lg font-medium transition-colors flex items-center justify-center gap-2',
+                selectedFile && name.trim() && !isLoading
+                  ? 'bg-primary text-white hover:bg-primary/80'
+                  : 'bg-primary/50 text-white/50 cursor-not-allowed'
+              )}
+            >
+              {isLoading ? (
+                <>
+                  <div className="w-4 h-4 border-2 border-white/30 border-t-white rounded-full animate-spin" />
+                  Hochladen...
+                </>
+              ) : (
+                <>
+                  <Upload className="w-4 h-4" />
+                  Hochladen
+                </>
+              )}
+            </button>
+          </div>
+        </form>
+      </div>
+    </div>
+  );
+}
diff --git a/client/src/features/library/index.ts b/client/src/features/library/index.ts
new file mode 100644
index 0000000..8aeef46
--- /dev/null
+++ b/client/src/features/library/index.ts
@@ -0,0 +1,3 @@
+export { LibraryPage } from './components/library-page';
+export { UploadMapModal } from './components/upload-map-modal';
+export { CreateCombatantModal } from './components/create-combatant-modal';
diff --git a/docs/BATTLE_TODO.md b/docs/BATTLE_TODO.md
new file mode 100644
index 0000000..ee7d190
--- /dev/null
+++ b/docs/BATTLE_TODO.md
@@ -0,0 +1,134 @@
+# Battle Screen - TODO
+
+## Phase 2: Grid System
+
+### Frontend
+- [ ] `grid-overlay.tsx` - Verbessertes Grid-Rendering mit Snap-Preview
+- [ ] `grid-config-modal.tsx` - Grid konfigurieren (nur GM)
+  - Grid-Größe anpassen (Spalten x Reihen)
+  - Grid-Offset für vorgezeichnete Maps einstellen
+  - Live-Preview beim Anpassen
+  - Zellenfarbe und Transparenz
+- [ ] Snap-to-Grid beim Token-Platzieren
+- [ ] Grid Ein-/Ausblenden Toggle (bereits vorhanden, verbessern)
+
+---
+
+## Phase 3: Token Management
+
+### Frontend
+- [ ] `add-pc-modal.tsx` - PCs aus Kampagne hinzufügen (mit Filter/Suche)
+- [ ] `add-npc-modal.tsx` - NPCs aus Templates hinzufügen
+- [ ] `create-combatant-modal.tsx` - Neues NPC-Template erstellen
+  - Name, Level, HP, AC
+  - Rettungswürfe (Fort, Ref, Will)
+  - Wahrnehmung, Geschwindigkeit
+  - Fähigkeiten mit Aktionskosten
+  - Avatar-Upload
+- [ ] `token-detail-panel.tsx` - Seitenpanel für Token-Details
+  - HP-Management (Schaden/Heilung)
+  - Zustand hinzufügen/entfernen
+  - Notizen
+  - Statistiken anzeigen (für NPCs)
+- [ ] `initiative-tracker.tsx` - Initiativreihenfolge
+  - Sortierte Liste aller Tokens
+  - Aktueller Zug markiert
+  - Nächster/Vorheriger Zug
+  - Verzögern-Funktion
+
+### Backend WebSocket Events
+- [ ] `token_conditions_changed` - Zustände aktualisiert
+- [ ] `turn_started` - Zug beginnt (für aktiven Token)
+- [ ] `delay_turn` - Zug verzögern
+
+---
+
+## Phase 4: Player View
+
+### Frontend
+- [ ] `battle-player-view.tsx` - Route: `/campaigns/:id/battle/view`
+  - Vollbild-Ansicht für Spieler (TV-Modus)
+  - Read-only (keine Token-Manipulation)
+  - Sync via gleicher WebSocket-Room
+- [ ] `battle-tv-window.tsx` - Pop-out Window Logik
+  - "TV-Modus öffnen" Button
+  - Separates Browser-Fenster
+  - Automatische Größenanpassung
+
+### Berechtigungen
+| Feature | GM View | Player View |
+|---------|---------|-------------|
+| Tokens bewegen | Ja | Nein |
+| PC HP sehen | Ja (Zahlen) | Ja (Zahlen) |
+| NPC HP sehen | Ja (Zahlen) | Nein (nur Blut-Effekt bei <20%) |
+| NPC-Stats sehen | Ja | Nein |
+| Initiative bearbeiten | Ja | Nein |
+| Grid konfigurieren | Ja | Nein |
+
+---
+
+## Phase 5: Polish & Erweiterte Features
+
+### Drag & Drop
+- [ ] Touch-Support für mobile Geräte
+- [ ] Drag-Preview mit Zielzelle hervorheben
+- [ ] Multi-Select (Shift+Klick)
+- [ ] Mehrere Tokens gleichzeitig bewegen
+
+### Visuelle Verbesserungen
+- [ ] Condition-Badges auf Tokens
+  - Icon für häufige Zustände (Frightened, Slowed, etc.)
+  - Anzahl bei gestuften Zuständen
+- [ ] Blut-Effekt bei niedrigen HP (<20%)
+- [ ] Token-Avatar anstatt Initialen (wenn vorhanden)
+- [ ] Verschiedene Token-Formen (rund, eckig)
+- [ ] Größen-Indikator für Large/Huge/Gargantuan
+
+### Kampf-Tools
+- [ ] `combat-log.tsx` - Letzte Aktionen anzeigen
+  - Token bewegt
+  - Schaden erhalten
+  - Zustand hinzugefügt
+  - Initiative geändert
+- [ ] `measure-tool.tsx` - Entfernung messen
+  - Klick & Drag für Linie
+  - Entfernung in Fuß anzeigen
+  - Diagonal-Bewegung nach PF2e-Regeln
+- [ ] `area-tool.tsx` - Flächeneffekte
+  - Kegel, Linie, Emanation, Burst
+  - Größe einstellen
+  - Betroffene Felder hervorheben
+
+### Map-Features
+- [ ] Fog of War (nur GM sieht alles)
+- [ ] Mehrere Ebenen (Untergrund, Obergeschoss)
+- [ ] Zoom & Pan
+- [ ] Map-Marker / Notizen
+
+---
+
+## Technische Verbesserungen
+
+### Performance
+- [ ] Canvas-basiertes Rendering statt DOM für große Maps
+- [ ] Token-Position nur bei Release senden (nicht während Drag)
+- [ ] Lazy Loading für Token-Avatare
+
+### Backend
+- [ ] Combat Log in Datenbank speichern
+- [ ] Battle Session Snapshots (Undo/Redo)
+- [ ] Automatisches Aufräumen inaktiver Sessions
+
+---
+
+## Prioritäten
+
+1. **Hoch** - Grid Config Modal (Phase 2)
+2. **Hoch** - Initiative Tracker (Phase 3)
+3. **Hoch** - Player View / TV-Modus (Phase 4)
+4. **Mittel** - Token Detail Panel mit HP-Management
+5. **Mittel** - Condition Badges
+6. **Mittel** - Combatant Template erstellen
+7. **Niedrig** - Measure Tool
+8. **Niedrig** - Combat Log
+9. **Niedrig** - Fog of War