Index: binaries/data/mods/public/gui/common/functions_utility.js
===================================================================
--- binaries/data/mods/public/gui/common/functions_utility.js
+++ binaries/data/mods/public/gui/common/functions_utility.js
@@ -130,24 +130,6 @@
 	}
 }
 
-// Filter out conflicting characters and limit the length of a given name.
-// @param name Name to be filtered.
-// @param stripUnicode Whether or not to remove unicode characters.
-// @param stripSpaces Whether or not to remove whitespace.
-function sanitizePlayerName(name, stripUnicode, stripSpaces)
-{
-	// We delete the '[', ']' characters (GUI tags) and delete the ',' characters (player name separators) by default.
-	var sanitizedName = name.replace(/[\[\],]/g, "");
-	// Optionally strip unicode
-	if (stripUnicode)
-		sanitizedName = sanitizedName.replace(/[^\x20-\x7f]/g, "");
-	// Optionally strip whitespace
-	if (stripSpaces)
-		sanitizedName = sanitizedName.replace(/\s/g, "");
-	// Limit the length to 20 characters
-	return sanitizedName.substr(0,20);
-}
-
 function singleplayerName()
 {
 	return Engine.ConfigDB_GetValue("user", "playername.singleplayer") || Engine.GetSystemUsername();
Index: binaries/data/mods/public/gui/lobby/prelobby.js
===================================================================
--- binaries/data/mods/public/gui/lobby/prelobby.js
+++ binaries/data/mods/public/gui/lobby/prelobby.js
@@ -91,8 +91,8 @@
 		continueButton.enabled = false;
 		feedback.caption = translate("Please enter your username");
 	}
-	// Check that they are using a valid username.
-	else if (username != sanitizePlayerName(username, true, true))
+
+	if (!username.match(/^[a-z0-9._-]*$/i) || username.length > 20);
 	{
 		continueButton.enabled = false;
 		feedback.caption = translate("Usernames can't contain \\[, ], unicode, whitespace, or commas");
@@ -180,8 +180,8 @@
 		{
 			Engine.PopGuiPage();
 			Engine.SwitchGuiPage("page_lobby.xml");
-			Engine.ConfigDB_CreateValue("user", "playername.multiplayer", sanitizePlayerName(username, true, true));
-			Engine.ConfigDB_WriteValueToFile("user", "playername.multiplayer", sanitizePlayerName(username, true, true), "config/user.cfg");
+			Engine.ConfigDB_CreateValue("user", "playername.multiplayer", username);
+			Engine.ConfigDB_WriteValueToFile("user", "playername.multiplayer", username, "config/user.cfg");
 			Engine.ConfigDB_CreateValue("user", "lobby.login", username);
 			Engine.ConfigDB_WriteValueToFile("user", "lobby.login", username, "config/user.cfg");
 			// We only store the encrypted password, so make sure to re-encrypt it if changed before saving.