The Enigma engine (also called the Blitzkrieg engine) is a game engine developed by Nival Interactive that is used in several real-time tactics video games, including their own games, Blitzkrieg and Blitzkrieg 2. Games that have utilized this engine include Blitzkrieg (with several stand-alone add-ons), Stalingrad, Cuban Missile Crisis: The Aftermath, Frontline: Fields of Thunder, World War I, Talvisota: Icy Hell and X-Team: Day of Freedom. The game Desert Law (2005) by Arise also uses a modified version of the engine.
Graphics deliver realistic 3D rendered isometric terrain and details include seasons, climatic zones and weather conditions which can affect game play. Blood is present although it can be deactivated. The player has the ability to build pontoon bridges, dig trenches, lay mines, resupply and repair units or call in air support but there are no resources apart from warehouses which can be captured present in the game. Virtually everything can be destroyed including buildings and bridges. Forests can be flattened by tanks or artillery. Each unit of a respective nation speaks its own language, adding immensely to the immersion.
Later versions of this engine forgo isometric graphics in favor of true 3D graphics, facilitating true line-of-sight and line-of-fire.