diff --git a/sources/Users/User.uc b/sources/Users/User.uc
index 18ecc36..73fa259 100644
--- a/sources/Users/User.uc
+++ b/sources/Users/User.uc
@@ -31,7 +31,15 @@ var private int     key;
 var private Database    persistentDatabase;
 //  Pointer to this user's "settings" data in particular
 var private JSONPointer persistentSettingsPointer;
-
+//      Groups to which caller `User` belongs to.
+//      Every user always belongs to group "everyone", so it is never listed
+//  here.
+//      Local user groups are not available for modification and are only loaded
+//  from configs, so `userGroups` might duplicate groups from `localUserGroup`,
+//  allowing to add them to editable sources (database).
+//      Group names are stored in the lower register.
+var private array<Text> userGroups; // user groups loaded from database
+var private array<Text> localUserGroups; // user groups loaded from local files
 var private LoggerAPI.Definition errNoUserDataDatabase;
 
 protected function Finalizer()
@@ -52,6 +60,7 @@ protected function Finalizer()
  *      Initialization should (and can) only be done once.
  *      Before a `Initialize()` call, any other method calls on such `User`
  *  must be considerate to have undefined behavior.
+ *      DO NOT CALL THIS METHOD MANUALLY.
  */
 public final function Initialize(UserID initID, int initKey)
 {
@@ -60,6 +69,7 @@ public final function Initialize(UserID initID, int initKey)
     if (initID != none) {
         initID.NewRef();
     }
+    LoadLocalGroups();
 }
 
 /**
@@ -85,6 +95,150 @@ public final function int GetKey()
     return key;
 }
 
+//  Loads locally defined groups from the "AcediaUserGroups.ini" config
+private final function LoadLocalGroups()
+{
+    local int           i, j;
+    local string        mySteamID;
+    local UserGroup     nextGroupConfig;
+    local array<string> nextUserArray;
+    local array<Text>   availableGroups;
+
+    if (id == none) {
+        return;
+    }
+    class'UserGroup'.static.Initialize();
+    mySteamID = _.text.IntoString(id.GetSteamID64String());
+    availableGroups = class'UserGroup'.static.AvailableConfigs();
+    //  Go over every group
+    for (i = 0; i < availableGroups.length; i += 1)
+    {
+        nextGroupConfig = UserGroup(
+            class'UserGroup'.static.GetConfigInstance(availableGroups[i]));
+        //  Add group as local if it has our ID recorded
+        nextUserArray = nextGroupConfig.user;
+        for (j = 0; j < nextUserArray.length; j += 1)
+        {
+            if (nextUserArray[j] == mySteamID)
+            {
+                localUserGroups[localUserGroups.length] =
+                    availableGroups[i].LowerCopy();
+            }
+        }
+        _.memory.Free(nextGroupConfig);
+    }
+    _.memory.FreeMany(availableGroups);
+}
+
+/**
+ *  Adds caller user into new group, specified by `newGroup`.
+ *  This group must exist for the method to succeed.
+ *
+ *  @param  newGroup    Name of the group to add caller `User` into.
+ */
+public final function AddGroup(Text newGroup)
+{
+    local int i;
+
+    if (newGroup == none)                           return;
+    if (class'UserGroup'.static.Exists(newGroup))   return;
+
+    for (i = 0; i < userGroups.length; i += 1)
+    {
+        if (newGroup.Compare(userGroups[i], SCASE_INSENSITIVE)) {
+            return;
+        }
+    }
+    userGroups[userGroups.length] = newGroup.LowerCopy();
+}
+
+/**
+ *  Removes caller user from the given group `groupToRemove`.
+ *
+ *  @param  groupToRemove   Name of the group to remove caller `User` from.
+ *  @return `true` if user was actually removed from the group and `false`
+ *      otherwise (group doesn't exist or user didn't belong to it).
+ */
+public final function bool RemoveGroup(Text groupToRemove)
+{
+    local int i;
+
+    if (groupToRemove == none) {
+        return false;
+    }
+    for (i = 0; i < userGroups.length; i += 1)
+    {
+        if (groupToRemove.Compare(userGroups[i], SCASE_INSENSITIVE))
+        {
+            userGroups[i].FreeSelf();
+            userGroups.Remove(i, 1);
+            return true;
+        }
+    }
+    return false;
+}
+
+/**
+ *  Checks whether caller `User` belongs to the group specified by
+ *  `groupToCheck`.
+ *
+ *  @param  groupToCheck    Name of the group to check for whether caller `User`
+ *      belongs to it.
+ *  @return `true` if caller `User` belongs to the group `groupToCheck` and
+ *      `false` otherwise.
+ */
+public final function bool IsInGroup(Text groupToCheck)
+{
+    local int i;
+
+    if (groupToCheck == none) {
+        return false;
+    }
+    for (i = 0; i < userGroups.length; i += 1)
+    {
+        if (groupToCheck.Compare(userGroups[i], SCASE_INSENSITIVE)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+/**
+ *  Returns array with names of all groups to which caller user belongs to.
+ *
+ *  @return Array of names of the groups that caller user belongs to.
+ *      Guaranteed to not contain duplicates or `none` values.
+ */
+public final function array<Text> GetGroups()
+{
+    local int           i, j;
+    local bool          duplicate;
+    local array<Text>   result;
+
+    for (i = 0; i < localUserGroups.length; i += 1) {
+        result[result.length] = localUserGroups[i].Copy();
+    }
+    for (i = 0; i < userGroups.length; i += 1)
+    {
+        duplicate = false;
+        //  Check `userGroups[i]` for being a duplicate from `localUserGroups`
+        for (j = 0; j < localUserGroups.length; j += 1)
+        {
+            //  No need for `SCASE_INSENSITIVE`, since user group names
+            //  are stored in lower case
+            if (userGroups[i].Compare(localUserGroups[j]))
+            {
+                duplicate = true;
+                break;
+            }
+        }
+        if (!duplicate) {
+            result[result.length] = userGroups[i].Copy();
+        }
+    }
+    return result;
+}
+
 /**
  *  Reads user's persistent data saved inside group `groupName`, saving it into
  *  a collection using mutable data types.