The Making Of: Pitfall!
Format: Atari 2600
Developer: David Crane
Pitfall Harry is stuck in the jungle. He’s racing through, swinging from vines, jumping on alligator heads, grabbing treasures and looking for shortcuts. For David Crane, the creator and programmer of Pitfall!, one of the first Activision games for the Atari 2600, the hardest part of the game wasn’t avoiding the scorpions or coiled snakes, it was trying to jam a lot of game into only 4K of memory.
“I loved the technical challenge of designing games on the 2600,” says Crane of Atari’s first console unit. He and his fellow game developers for the much-loved 2600 were more than aware of the restrictions they were dealing with. They would have to write an entire game, complete with graphics, gameplay, sound effects and all the scoring in just 4096 bytes. You could hardly let your imagination run wild with that kind of memory size. “A lot of the game features in those days were not what you could think of, but what you could actually achieve.” At that time, Crane’s complete design philosophy was to first think of a clever and original technical achievement and then to build a game around it.
“The ‘little running man’ was really the technical hurdle,” says Crane. “If you think back to the state-of-the-art videogames of the late-’70s, there were very few attempts at animated figures in games. You controlled tanks, jet planes, Pong paddles and so on because the limited number of display pixels severely restricted the creation of smooth animation. I had developed a realistic-looking human character in 1979 before I had a game idea that needed one. The difficulty was coming up with a game that made sense to have a little running man in it.” For three years, Crane tested the character in different scenarios such as a ‘cops and robbers’ game, but it didn’t work and was therefore shelved.
In 1982, while he was between games, Crane finally decided he would figure out a game for the ‘little running man.’ “I sat down with a blank sheet of paper and drew a stick figure in the centre. I said, ‘Okay, I have a little running man and let’s put him on a path’ (two more lines drawn on the paper). ‘Where is the path? Let’s put it in a jungle’ (draw some trees). ‘Why is he running?’ (draw treasures to collect, enemies to avoid and so on). And Pitfall! was born.” The man became known as Pitfall Harry. “This entire process took about ten minutes. About 1,000 hours of programming later, the game was complete. In that era we said we spent 90 per cent of our time writing the last ten per cent of the game.”
It’s no surprise that the film Raiders of the Lost Ark, which was released in 1981, influenced the design of Pitfall!, and there was another apparent nod to Tarzan with the presence of the swinging vines. But not so obvious were the introductions of the alligators. “I remembered from deep in my childhood a pair of cartoon characters (Magpies) called Heckle and Jekyll. They had a sequence during which they would run across the heads of alligators, barely escaping the jaws. I thought that would make for an interesting sequence in the game.”
Leaping across alligator heads turned out to be Crane’s favourite aspect of the game. “The first time you crossed the alligators you did so by carefully waiting for the mouths to close, jumping onto the closed mouth, tapping the joystick to move over to stand on the forehead, and waiting until the mouth opened and closed again before moving on. But once you got really good you could sail non-stop across them by exactly aiming your landing to hit the forehead of the first alligator and immediately jumping again to the next one.”
Creating this enjoyable sequence in the game required a small programming tweak. In the original design, to jump from one alligator head to the other the player had to move the joystick and jump at exactly the same time. “This proved to be almost impossible to play. So I changed the code to allow you to direct Harry’s jump to the side, if you moved the joystick within a small instant from the time you pressed the button to jump. From a programming standpoint this was a tiny change, but it changed the gameplay from nearly impossible to an easily learned skill.” It was this design decision, and many others influenced by other programmers, that made Activision games such as Pitfall! so much fun. “It was all in the tiny details,” says Crane.
“The world of Pitfall Harry is a circular path 254 screens in circumference. The game ROM contains only 4Kb of memory, so there isn’t enough memory to hold both Harry’s graphic frames and the definitions for 254 screens. I solved this problem on Pitfall! by creating an algorithm that defined every screen mathematically. The actual definition of the entire world took less than 50 bytes of ROM.”