Eastern Front (1941)

Eastern Front is a corps-level simulation of the first 41 weeks of Operation Barbarossa, the German invasion of the Soviet Union in 1941. The player controls the Germans, in white, while the computer plays the Russians, in red. Units are represented as boxes for armored corps or cavalry, and crosses for infantry, an attempt to replicate conventional military symbols given the low resolution.

The playfield is 2+1⁄3 screens wide, 4+1⁄3 screens tall, and uses 18 colors. The screen shows only 1⁄9 of the entire map at one time, smooth-scrolling around it when the joystick-controlled cursor reaches the edges of the screen. According to creator Chris Crawford, it is the first wargame with a smooth-scrolling map. The map covers the area from just north of Leningrad at the top to Sevastopol at the bottom, and from Warsaw on the left to just east of Stalingrad on the right.

After writing Tanktics, which simulated German and Soviet tank battles during World War II, Crawford wrote the first version of what he called Ourrah Pobieda (Russian for "Horray, Victory!") in May and June 1979 on a Commodore PET using Commodore BASIC. The game was at the time a division-level simulation of combat on the Eastern Front. He described the initial version as "dull, confusing, and slow", and did not return to the project for 15 months.

After he began working for Atari, in September 1980 he saw a fellow employee demonstrate smooth scrolling in a text window on an Atari 8-bit and realized the technique's potential for a war game. By December he produced a smoothly scrolling map of Russia, in January 1981 produced a written description of the design for what he by now envisioned as a "48K disk-based game with fabulous graphics" written in assembly language, and began working 20 hours a week during nights and weekends to produce a demonstrable game by the Origins Convention in July.

Eastern Front received critical praise from contemporary magazines. Computer Gaming World in 1981 called it "to this date, the most impressive computer wargame on the market". The review praised the graphics and the artificial intelligence, noted its pondering, and suggested that the game was a killer app for Atari computers. Six years later the magazine still rated the game five out of five points, stating "obsolete by contemporary programming standards, it is still fun to play", and in 1993 rated the game four stars out of five.

Creative Computing called Eastern Front "one of the very best war games available for a personal computer ... nearly every aspect of the game is a technical masterpiece", praising its artificial intelligence and "magnificent" scrolling map. The magazine concluded that it was "also a virtuoso demonstration of the awesome built-in capabilities of the Atari computer. This game literally could not be done on any other computer in as satisfactory an execution".

While the game was still being sold, Crawford released its source code through APX as a separate, commercial product targeted at developers. He was surprised that while it sold well, no other game used it. He also released a scenario editor, but only one pre-packaged set of user-created scenarios is known.

Crawford used many of the ideas from Eastern Front in Legionnaire for Avalon Hill in 1982. Legionnaire uses the same map engine to simulate the Roman legions fighting the barbarians, but modifies it to move units in real time.