In addition to a turn-based tactical combat layer, the "X-COM" series also possesses a real-time 3D strategic layer, complete with global defensive map as well as a technology tree that the player must research in order to unlock new weapons and armor. "Jagged Alliance 2" features a country sector map with fortified towns and roving bands of enemies that must be defeated before entering the capital city of Meduna. "Knights in the Nightmare" (2009) combines elements of traditional tactical RPGs with bullet hell–style shoot 'em up gameplay.