Tron Deadly Discs (Mattel Electronics, 1982) was one of the three Tron-themed games that Mattel Electronics developed for the Intellivision, hoping to capitalize on the popularity of the 1982 movie. As with most Intellivision games, the developers did a wonderful job of overcoming the inherent limitations of the graphics and sound of the Intellivision system. By focusing on gameplay and control, they managed to develop an extremely fun, if somewhat repetitive game. The characters in the game were the generic Mattel stick figure animations used in most of their games. Tron Deadly Discs was one-player only. It was also available for the Atari 2600, but the graphics were even worse.
The idea centers around the identity discs that Tron himself and certain other programs in the movie kept on their backs and used as weapons. In the movie, the discs were thrown like Frisbees (in fact the cast were trained by a professional Frisbee team) and traveled in a way that implied they were remotely controlled by their user, the initial throwing doing little more than providing momentum and general direction. The discs would curve, turn, and gain altitude in a way that was clearly unnatural for a regular Frisbee. In fact, in Tron's final confrontation with Sark, the discs could make multiple passes and strikes per throw. In the game, the discs would travel in a straight line and were not controllable in flight, except that they would follow the player to automatically return to the character after it was thrown. The disc was harmless when returning.
The game plays like one of the gladiator games from the movie, with a few new elements added. The player starts out in the center of a square arena with a large grid pattern on the floor and thick walls on all four sides. The enemies come out of any of three hidden doors in each wall, three at a time, to attack the player. Both the enemies and the player can throw their discs at each other to attack, but otherwise cannot damage each other. Two characters simply run past or through each other if they collide.
The Intellivision controller looked very different from any other video game controller designed before or since, which some people liked and other people found aggravating. It was a tall rectangle with a control disc at the bottom and a 12 key pad at the top, marked like a telephone keypad. The control disc operated like a joystick except flat, designed to be operated with the thumb. The controller was designed so plastic inserts could be slid over the keypad to label the controls for each individual game. There were also four side buttons, two on each side of the controller. Tron only used the keypad numbers 1-9 and the control disc.
Controlling the player:
The control disc was used to run around the screen, but the real fun was using the keypad to throw the disc. Using the keys 1-9 (except 5) would throw the disc in a straight line in that direction – for example 1, being at the top-left, would throw the disc diagonally up and to the left. When the disc reached the edge of the screen or another solid object, or if the player pushed another keypad button, it would return to the player, following the character wherever it would run. Additionally, the player could press the 5 key to crouch into a defensive position, using the control disc to block in any specific direction except for directly up and down. Enemy discs blocked would shatter, but the enemy would get a new disc after a few seconds, thrown from off screen. The player could not run while blocking, but pushing the 5 key again would return to the upright position.
Enemy soldiers and damage:
Most enemy soldiers had discs just like the player, and more advanced enemies were more accurate with them. The first enemies could be killed, or de-rezzed, with one hit, and later enemies took two or three hits. Certain enemies were even smart enough to be able to block the player's disc, which would shatter just like an enemy disc. After a few seconds the player would receive a new disc thrown from off screen.
Enemies would attack in groups of three, entering the arena from any of three doors on each of the four arena walls, and attack the player. Most enemies would be armed with discs, but the most advanced enemy soldiers were armed with some sort of pole weapon (seen carried by the guards in the movie) which they could not throw, but would kill the player instantly if they made contact. Otherwise it took three hits to kill the character with disc hits, except for the most advanced disc-throwing enemy who's disc counted for two hits. The player only had one life and no way to get additional armor.
Enemies or the player hit with a lethal blow would de-resolution, or de-rezz, and the killing disc would pass through them. De-rezzing happened in a very similar manner to the movie, discrete blocks of the character's graphic would disappear until the whole character was gone. Characters only wounded would crouch, stunned, briefly, and when they got up they ran more slowly (in this case the disc would not pass through and would return to the owner). After being hit twice, the player would run so slowly that the final hit was all but inevitable. They would slowly heal over time, signaled by running faster again. When an enemy was killed, if the wave was not over another one would enter the arena to keep a maximum of three enemies on screen.
Doors:
The doors the enemy soldiers ran out of stayed open for a little while after they came through. If the player threw his disc at the door while it was open, or ran directly into it, the door would jam and stay open. If the player could jam open two doors on opposite sides of the screen, the character could cross the screen using them, like Pac-Man. This would greatly confuse the simple enemy AI and was a significant advantage. The enemy AI never used the doors except to enter the arena. Jammed doors could only be closed by the Recognizer.
The Recognizer:
The Recognizer was the large, blocky vehicle in the movie shaped a bit like a capital Greek Π. In the game they fill a role unseen in the movie. Between waves of enemies, the Recognizer would slowly enter the arena from the North and stop in the center. Once positioned, it would throw new doors into any jammed open portals until they were all sealed or the player managed to destroy it. Meanwhile a stun beam would slowly follow the player around the arena, and if caught the player wouldn't be able to move until the Recognizer finished its work.
The Recognizer could only be destroyed by throwing the disc at its "eye", a yellow square in the pilot's compartment which would slide side to side, making it difficult to hit. The doors thrown by the Recognizer would simply pass through the player without doing any damage, but touching the Recognizer was fatal. Discs impacting on the Recognizer's invulnerable armor would bounce off in an uncontrolled manner, and it would take a second before the disc would return to the player. If it managed to seal all the doors, it would pick one of the four cardinal directions at random and leave the arena. Likewise if it was destroyed, which made sparks fly from the pilot's compartment as it left the arena. The farther in the game the player got, the faster the Recognizer would move and throw doors. No other enemies would be on screen with the Recognizer.
Infinite levels:
Like many games from the early 80s, Tron Deadly Discs did not have a goal or an ending. Players would play for points, trying to see how far they could advance in the game. The levels got progressively harder as the enemies got more advanced, throwing discs more accurately, armed with stronger discs, and finally being able to kill the player with a single touch, as well as taking more hits to kill. The player meanwhile had the same abilities throughout the game, running no faster and getting no additional armor or weaponry. It was also terribly addicting with excellent replay value. No matter how good you got, making it to a higher level brought a bigger challenge.