diff --git a/base/src/main/java/de/staropensource/sosengine/base/types/ImmutableMap.java b/base/src/main/java/de/staropensource/sosengine/base/types/ImmutableMap.java
new file mode 100644
index 0000000..56c3d87
--- /dev/null
+++ b/base/src/main/java/de/staropensource/sosengine/base/types/ImmutableMap.java
@@ -0,0 +1,163 @@
+/*
+ * STAROPENSOURCE ENGINE SOURCE FILE
+ * Copyright (c) 2024 The StarOpenSource Engine Contributors
+ * Licensed under the GNU Affero General Public License v3
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.staropensource.sosengine.base.types;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.BiFunction;
+
+/**
+ * An unmodifiable {@link Map}.
+ * {@inheritDoc}
+ *
+ * @since 1-alpha1
+ */
+@SuppressWarnings({ "unused" })
+public class ImmutableMap<K, V> extends HashMap<K, V> {
+    /**
+     * Constructor.
+     *
+     * @since 1-alpha1
+     */
+    public ImmutableMap() {}
+
+    /**
+     * Converts some {@link Map} into a {@link ImmutableMap}.
+     *
+     * @param map {@link Map} to convert
+     * @since 1-alpha1
+     */
+    public ImmutableMap(@NotNull Map<K, V> map) {
+        for (K key : map.keySet())
+            put(key, map.get(key));
+    }
+
+    /**
+     * Note: This method is a stub.<br/>
+     * {@inheritDoc}
+     *
+     * @since 1-alpha1
+     */
+    @Nullable
+    @Override
+    public V put(K key, V value) {
+        return null;
+    }
+
+    /**
+     * Note: This method is a stub.<br/>
+     * {@inheritDoc}
+     *
+     * @since 1-alpha1
+     */
+    @Nullable
+    @Override
+    public V remove(Object key) {
+        return null;
+    }
+
+    /**
+     * Note: This method is a stub.<br/>
+     * {@inheritDoc}
+     *
+     * @since 1-alpha1
+     */
+    @Override
+    public void putAll(@NotNull Map<? extends K, ? extends V> m) {}
+
+    /**
+     * Note: This method is a stub.<br/>
+     * {@inheritDoc}
+     *
+     * @since 1-alpha1
+     */
+    @Override
+    public void clear() {}
+
+    /**
+     * Note: This method is a stub.<br/>
+     * {@inheritDoc}
+     *
+     * @since 1-alpha1
+     */
+    @Override
+    public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {}
+
+    /**
+     * Note: This method is a stub.<br/>
+     * {@inheritDoc}
+     *
+     * @since 1-alpha1
+     */
+    @Nullable
+    @Override
+    public V putIfAbsent(K key, V value) {
+        return null;
+    }
+
+    /**
+     * Note: This method is a stub.<br/>
+     * {@inheritDoc}
+     *
+     * @since 1-alpha1
+     */
+    @Override
+    public boolean remove(Object key, Object value) {
+        return false;
+    }
+
+    /**
+     * Note: This method is a stub.<br/>
+     * {@inheritDoc}
+     *
+     * @since 1-alpha1
+     */
+    @Override
+    public boolean replace(K key, V oldValue, V newValue) {
+        return false;
+    }
+
+    /**
+     * Note: This method is a stub.<br/>
+     * {@inheritDoc}
+     *
+     * @since 1-alpha1
+     */
+    @Nullable
+    @Override
+    public V replace(K key, V value) {
+        return null;
+    }
+
+    /**
+     * Note: This method is a stub.<br/>
+     * {@inheritDoc}
+     *
+     * @since 1-alpha1
+     */
+    @Nullable
+    @Override
+    public V merge(K key, @NotNull V value, @NotNull BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
+        return null;
+    }
+}