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Eastern Front (computer game)
Encyclopedia
Eastern Front is a computer game for the Atari 8-bit
series created by Chris Crawford
in 1981. Recreating the German invasion of Russia
during World War II, Eastern Front covers the historical area of operations during the 1941–1942 period. The player commands German units at the corps
level and must contend with the computer-control Russians, as well as terrain, weather, supplies and even unit morale
and fatigue
.
Eastern Front was widely lauded in the press. It is considered to be one of the first computer wargames
that could compete with paper-and-pencil games in terms of depth of play. According to Crawford, it is the first wargame to feature a smooth-scrolling map.
Eastern Front puts the user in control of 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 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. 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. The terrain is varied, including flatland, forests, mountains, rivers and swamps, each with their own effects on movement. Cities are also displayed, and are a major source of "victory points", the player's score.
Most user input is via the joystick, which is used in place of a mouse in selecting units and entering orders. The game is modal, switching between an order entry mode and a combat mode. During order entry the joystick is used to select units and enter movement in the four cardinal directions. Up to eight orders can be entered for any unit, the units attempt to move as far as possible in any given turn. Adding new orders required the user to watch an animation showing existing ones, which is slow.
After entering orders, the combat phase is started by pressing the function key
. The screen shows combat by flashing the "attacked" unit, which might be forced to retreat, or be destroyed outright. When all possible movement and combat is exhausted, the game returns to the order-entry phase. The number of grid squares moved during one turn was limited by the terrain the units moved over. Each turn represents one week in-game time, and the game ends on March 29, 1942, after 41 turns.
The game engine included a number of features that dramatically increased "depth" compared to other wargames of the era. This includes muster and combat strengths, which simulated losses due to combat, as well as reinforcements that would slowly increase a unit back to muster strength over time. Supply lines are also simulated, and surrounding the enemy to cut off their supplies was an important strategy for the human player, who faces an overwhelming enemy numerical superiority. The game also includes the concept of "area of influence" which allows front lines to be constructed without requiring contiguous lines of units.
The most obvious effect in terms of gameplay was the changing of the seasons, with the rivers and land freezing from the north down. Winter and spring weather dramatically reduces mobility and supply levels, at which point the game becomes purely defensive for the German side. If the player can survive the winter, the arrival of spring offers a renewed offensive capability, but only for a short period before the game ends.
calculated its moves during the period between vertical blank interrupt
s (VBI). The rest of the game, what the user saw, was run during the VBI period of a few hundred cycles. According to Crawford in Chris Crawford on Game Design
, the system started with a basic "plan" and then applied any available cycles to trying variations on that plan, selecting higher-valued outcomes. A few thousand cycles were available between each VBI, so given a typical order-entry phase of a minute, the computer had millions of cycles to spend on refining its plan.
The AI was based on three basic measures of the game state: the strategic situation which attempted to take and hold cities, the tactical situation which attempted to block player movements, and the overall arrangement of the front line. The AI would first attempt to build a continuous front line in an attempt to prevent encirclements, it would then send additional units on intercept courses to block player movements, and finally any remaining units were sent to undefended cities.
Although the AI was not particularly strong, it made up for this with numbers. Against a player "playing fair" the computer could put up a credible defence. Direct fights were hopeless, as newly arriving units would eventually overwhelm the German forces. Crawford spent considerable time "tuning" the arrival of new units to balance the gameplay. In typical games, the player would attempt to break eastward, and encircle the ever-growing block of Russian units. The Russians were short of the highly mobile armored units, at least early in the game, so it was possible to outmaneuver them and cut off their supplies, drawn from the far right edge of the screen.
Unfortunately, there were ways to "game" the AI. One was to break the German forces into two blocks, and then advance them on alternate turns. The tactical part of the AI would attempt to intercept these movements, sending its mobile forces first one way, then the other, never actually making contact. Another strategy was to keep flanking forces behind a spearhead, which the AI would attempt to block. This would result in the computer forces clumping up in front of the Germans, allowing the wings to move in once motion was difficult.
One "bug" in the game engine was later exploited by players. Since the AI calculated its moves while the user entered their orders, reducing the amount of time the user took to plan their own moves reduced the quality of the computer response. This could be reduced to zero by pressing the key repeatedly, at which point neither the player or the computer would do anything. This way combat during the winter could be avoided entirely, allowing the player to break out the next spring with full-strength units.
Crawford approached Atari about selling the game, but the company felt that wargames
would not sell on the 8-bits. Instead he turned to the Atari Program Exchange
(APX), a mail-order operation that distributed 3rd party applications. Eastern Front became an APX best-seller, selling over 60,000 copies ($40,000 in royalties). The manager of APX noted that Eastern Front paid their bills. Crawford also released the source code
to the game on APX, at a higher price. He later expressed his surprise that while sales of the source code did seem to be strong, no 3rd-party games were ever released that were based on it. This code is now available on the internet, allowing it to be examined, although only within the Atari Assembler Editor
, perhaps in an emulator
.
The game was so successful that Atari asked Crawford to do a conversion to cartridge. Crawford took the time to make a new version, improving many aspects of the game. To improve the gameplay he revamped the AI code, and eliminated the ability to "fast forward" the game and avoid combat. Five "difficulty levels" were added, the "learner" mode with a single German unit in order to teach the user how to use the controls, and each level above that adding more units up to "advanced", which was identical to the original game. In the highest level, "expert", air force corps (Fliegercorp) were added, and the units could be placed in one of several "modes"; normal, assault, defend and move. In "expert" the user could also choose to start in either 1941 with the standard opening, or 1942, with fully developed lines deep within Russia. The new version also added the ability to save and restore games, colored cities to indicate ownership, and added city names to the in-game map (which were previously visible only in the manual). The conversion from APX to official Atari product was fairly rare, although Caverns of Mars
and Dandy
underwent similar conversions for the same reasons.
Crawford would go on to use many of the ideas pioneered in Eastern Front to produce Legionnaire for Avalon Hill
in 1982. Legionnaire used the same map engine to simulate the Roman legion
s fighting the barbarian
s, but modified the engine to move units in real-time. This made the game much more difficult to out-think than Eastern Front, as the human user was forced to find the enemy units on the map, plan strategy, and move their units at the same time.
magazine, calling it "truly magnificent". InfoWorld
rated it "Excellent" overall in December 1981, and later referred to it as one of "... the deepest computer games around." Creative Computing stated it was "one of the very best war games available", and awarded it Game-of-the-Year in 1981. Later reviews often use terms like "groundbreaking", "seminal" and "brilliant".
Atari 8-bit family
The Atari 8-bit family is a series of 8-bit home computers manufactured from 1979 to 1992. All are based on the MOS Technology 6502 CPU and were the first home computers designed with custom coprocessor chips...
series created by Chris Crawford
Chris Crawford (game designer)
Christopher Crawford is a computer game designer and writer noted for creating a number of important games in the 1980s, founding The Journal of Computer Game Design, and organizing the Computer Game Developers' Conference.- Biography :...
in 1981. Recreating the German invasion of Russia
Eastern Front (World War II)
The Eastern Front of World War II was a theatre of World War II between the European Axis powers and co-belligerent Finland against the Soviet Union, Poland, and some other Allies which encompassed Northern, Southern and Eastern Europe from 22 June 1941 to 9 May 1945...
during World War II, Eastern Front covers the historical area of operations during the 1941–1942 period. The player commands German units at the corps
Corps
A corps is either a large formation, or an administrative grouping of troops within an armed force with a common function such as Artillery or Signals representing an arm of service...
level and must contend with the computer-control Russians, as well as terrain, weather, supplies and even unit morale
Morale
Morale, also known as esprit de corps when discussing the morale of a group, is an intangible term used to describe the capacity of people to maintain belief in an institution or a goal, or even in oneself and others...
and fatigue
Combat stress reaction
Combat stress reaction , in the past commonly known as shell shock or battle fatigue, is a range of behaviours resulting from the stress of battle which decrease the combatant's fighting efficiency. The most common symptoms are fatigue, slower reaction times, indecision, disconnection from one's...
.
Eastern Front was widely lauded in the press. It is considered to be one of the first computer wargames
Wargame (video games)
Wargames are a subgenre of strategy video games that emphasize strategic or tactical warfare on a map, as well as historical accuracy.-History:The genre of wargame video games is derived from earlier forms of wargames...
that could compete with paper-and-pencil games in terms of depth of play. According to Crawford, it is the first wargame to feature a smooth-scrolling map.
Gameplay
- Unless otherwise noted, this section refers to the original game manual, available here
Eastern Front puts the user in control of 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 screen shows only 1/9 of the entire map at one time, smooth-scrolling around it when the joystick
Joystick
A joystick is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. Joysticks, also known as 'control columns', are the principal control in the cockpit of many civilian and military aircraft, either as a center stick or...
-controlled cursor reaches the edges of the screen. The map covers the area from just north of Leningrad
Leningrad
Leningrad is the former name of Saint Petersburg, Russia.Leningrad may also refer to:- Places :* Leningrad Oblast, a federal subject of Russia, around Saint Petersburg* Leningrad, Tajikistan, capital of Muminobod district in Khatlon Province...
at the top to Sevastopol
Sevastopol
Sevastopol is a city on rights of administrative division of Ukraine, located on the Black Sea coast of the Crimea peninsula. It has a population of 342,451 . Sevastopol is the second largest port in Ukraine, after the Port of Odessa....
at the bottom, and from Warsaw
Warsaw
Warsaw is the capital and largest city of Poland. It is located on the Vistula River, roughly from the Baltic Sea and from the Carpathian Mountains. Its population in 2010 was estimated at 1,716,855 residents with a greater metropolitan area of 2,631,902 residents, making Warsaw the 10th most...
on the left to just east of Stalingrad on the right. The terrain is varied, including flatland, forests, mountains, rivers and swamps, each with their own effects on movement. Cities are also displayed, and are a major source of "victory points", the player's score.
Most user input is via the joystick, which is used in place of a mouse in selecting units and entering orders. The game is modal, switching between an order entry mode and a combat mode. During order entry the joystick is used to select units and enter movement in the four cardinal directions. Up to eight orders can be entered for any unit, the units attempt to move as far as possible in any given turn. Adding new orders required the user to watch an animation showing existing ones, which is slow.
After entering orders, the combat phase is started by pressing the function key
Function key
A function key is a key on a computer or terminal keyboard which can be programmed so as to cause an operating system command interpreter or application program to perform certain actions...
. The screen shows combat by flashing the "attacked" unit, which might be forced to retreat, or be destroyed outright. When all possible movement and combat is exhausted, the game returns to the order-entry phase. The number of grid squares moved during one turn was limited by the terrain the units moved over. Each turn represents one week in-game time, and the game ends on March 29, 1942, after 41 turns.
The game engine included a number of features that dramatically increased "depth" compared to other wargames of the era. This includes muster and combat strengths, which simulated losses due to combat, as well as reinforcements that would slowly increase a unit back to muster strength over time. Supply lines are also simulated, and surrounding the enemy to cut off their supplies was an important strategy for the human player, who faces an overwhelming enemy numerical superiority. The game also includes the concept of "area of influence" which allows front lines to be constructed without requiring contiguous lines of units.
The most obvious effect in terms of gameplay was the changing of the seasons, with the rivers and land freezing from the north down. Winter and spring weather dramatically reduces mobility and supply levels, at which point the game becomes purely defensive for the German side. If the player can survive the winter, the arrival of spring offers a renewed offensive capability, but only for a short period before the game ends.
AI
The computer AIArtificial intelligence
Artificial intelligence is the intelligence of machines and the branch of computer science that aims to create it. AI textbooks define the field as "the study and design of intelligent agents" where an intelligent agent is a system that perceives its environment and takes actions that maximize its...
calculated its moves during the period between vertical blank interrupt
Vertical blank interrupt
A vertical blank interrupt is a programming technique used in some systems, notably video games and consoles, to allow program code to be run in the periods when the display hardware is turned off, waiting for the TV to complete its vertical blank.Since the vertical blank period occurs at the...
s (VBI). The rest of the game, what the user saw, was run during the VBI period of a few hundred cycles. According to Crawford in Chris Crawford on Game Design
Chris Crawford on Game Design
Chris Crawford on Game Design is a book about computer and video game design by Chris Crawford. Although referred to as the second edition of The Art of Computer Game Design, it is in fact a completely new book. It was published by Peachpit under the New Riders imprint in 2003...
, the system started with a basic "plan" and then applied any available cycles to trying variations on that plan, selecting higher-valued outcomes. A few thousand cycles were available between each VBI, so given a typical order-entry phase of a minute, the computer had millions of cycles to spend on refining its plan.
The AI was based on three basic measures of the game state: the strategic situation which attempted to take and hold cities, the tactical situation which attempted to block player movements, and the overall arrangement of the front line. The AI would first attempt to build a continuous front line in an attempt to prevent encirclements, it would then send additional units on intercept courses to block player movements, and finally any remaining units were sent to undefended cities.
Although the AI was not particularly strong, it made up for this with numbers. Against a player "playing fair" the computer could put up a credible defence. Direct fights were hopeless, as newly arriving units would eventually overwhelm the German forces. Crawford spent considerable time "tuning" the arrival of new units to balance the gameplay. In typical games, the player would attempt to break eastward, and encircle the ever-growing block of Russian units. The Russians were short of the highly mobile armored units, at least early in the game, so it was possible to outmaneuver them and cut off their supplies, drawn from the far right edge of the screen.
Unfortunately, there were ways to "game" the AI. One was to break the German forces into two blocks, and then advance them on alternate turns. The tactical part of the AI would attempt to intercept these movements, sending its mobile forces first one way, then the other, never actually making contact. Another strategy was to keep flanking forces behind a spearhead, which the AI would attempt to block. This would result in the computer forces clumping up in front of the Germans, allowing the wings to move in once motion was difficult.
One "bug" in the game engine was later exploited by players. Since the AI calculated its moves while the user entered their orders, reducing the amount of time the user took to plan their own moves reduced the quality of the computer response. This could be reduced to zero by pressing the key repeatedly, at which point neither the player or the computer would do anything. This way combat during the winter could be avoided entirely, allowing the player to break out the next spring with full-strength units.
Development and versions
Crawford, who worked at Atari at the time, developed Eastern Front during his own time for nine months. In a 1987 interview, he estimated he had worked a total of 800 hours on Eastern Front.Crawford approached Atari about selling the game, but the company felt that wargames
Wargame (video games)
Wargames are a subgenre of strategy video games that emphasize strategic or tactical warfare on a map, as well as historical accuracy.-History:The genre of wargame video games is derived from earlier forms of wargames...
would not sell on the 8-bits. Instead he turned to the Atari Program Exchange
Atari Program Exchange
Atari Program Exchange was a division of Atari, Inc. that distributed software for the Atari 8-bit family of home computers through a quarterly mail-order catalog. APX, the brain-child of Dale Yocam, started in February 1981 and guided by Fred Thorlin. APX published quarterly catalogs until 1984,...
(APX), a mail-order operation that distributed 3rd party applications. Eastern Front became an APX best-seller, selling over 60,000 copies ($40,000 in royalties). The manager of APX noted that Eastern Front paid their bills. Crawford also released the source code
Source code
In computer science, source code is text written using the format and syntax of the programming language that it is being written in. Such a language is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source...
to the game on APX, at a higher price. He later expressed his surprise that while sales of the source code did seem to be strong, no 3rd-party games were ever released that were based on it. This code is now available on the internet, allowing it to be examined, although only within the Atari Assembler Editor
Atari Assembler Editor
The Atari Assembler Editor cartridge was a program used to edit, compile and debug assembly language programs for the Atari 8-bit computers. It was programmed by Kathleen O'Brien of Shepardson Microsystems, Inc.- Details :...
, perhaps in an emulator
Emulator
In computing, an emulator is hardware or software or both that duplicates the functions of a first computer system in a different second computer system, so that the behavior of the second system closely resembles the behavior of the first system...
.
Caverns of Mars (computer game)
Caverns of Mars is a computer game for the Atari 8-bit computers, programmed by Greg Christensen and published by Atari Program Exchange in 1981. Christensen, a high-school student at the time, won a $3,000 prize from Atari, and his first royalty check was $18,000...
and Dandy
Dandy (computer game)
Dandy is a dungeon crawl computer game for the Atari 8-bit computers. Dandy was one of the first games to offer four-player cooperative play and a built-in editor...
underwent similar conversions for the same reasons.
Crawford would go on to use many of the ideas pioneered in Eastern Front to produce Legionnaire for Avalon Hill
Avalon Hill
Avalon Hill was a game company that specialized in wargames and strategic board games. Its logo contained its initials "AH", and it was often referred to by this abbreviation. It also published the occasional miniature wargaming rules, role-playing game, and had a popular line of sports simulations...
in 1982. Legionnaire used the same map engine to simulate the Roman legion
Roman legion
A Roman legion normally indicates the basic ancient Roman army unit recruited specifically from Roman citizens. The organization of legions varied greatly over time but they were typically composed of perhaps 5,000 soldiers, divided into maniples and later into "cohorts"...
s fighting the barbarian
Barbarian
Barbarian and savage are terms used to refer to a person who is perceived to be uncivilized. The word is often used either in a general reference to a member of a nation or ethnos, typically a tribal society as seen by an urban civilization either viewed as inferior, or admired as a noble savage...
s, but modified the engine to move units in real-time. This made the game much more difficult to out-think than Eastern Front, as the human user was forced to find the enemy units on the map, plan strategy, and move their units at the same time.
Reception
Eastern Front received critical praise from contemporary magazines. Jerry White gave it a rating of 9.3 out of 10 in A.N.A.L.O.G.A.N.A.L.O.G.
A.N.A.L.O.G. was an American computer magazine devoted to the Atari 8-bit home computer line. It was known for its "advanced" programs in comparison to most type-in magazines of the era, especially its main rival, ANTIC, another long-lived magazine devoted to the Atari 8-bit line...
magazine, calling it "truly magnificent". InfoWorld
InfoWorld
InfoWorld is an information technology online media and events business operating under the umbrella of InfoWorld Media Group, a division of IDG...
rated it "Excellent" overall in December 1981, and later referred to it as one of "... the deepest computer games around." Creative Computing stated it was "one of the very best war games available", and awarded it Game-of-the-Year in 1981. Later reviews often use terms like "groundbreaking", "seminal" and "brilliant".
General information and resources
- atariarchives.com; Eastern Front by Chris Crawford – APX Cat. No. 20050
- atariarchives.com; source code for Eastern Front – APX Cat. No. 20095
- atarimania.com; Atari Eastern Front (1941) information and scans (APX package).
- Atari Age; Eastern Front (1941), Atari – RX8039.