Tim Skelly was the designer and programmer of Rip Off, and has presented online the various methods he used to give the enemy tanks a high level of intelligence. This AI was one of the earliest examples of flocking behavior ever used in a video game. Apart from being impressive from a programming standpoint, this AI made the pirate tanks notoriously difficult to avoid, especially when the game's speed picked up after a few levels.
Best of all, Rip Off allowed two players to defend the fuel canisters at the same time, in cooperation. Most multiplayer games at the time forced players to take turns playing. Simultaneous multiplayer would have been unique enough, but allowing both players to team up to defeat computer-controlled enemies was brand new. (Fire Truck, an earlier co-op game, didn't have any enemies to speak of.) The original inspiration for cooperative gameplay in Rip Off was revealed by Skelly in an interview.
At the time, I was in a relationship with a disc jockey in Kansas City. The station she worked for was part of a large chain that periodically issued huge market research papers for the affiliates. Someone writing one of these papers had inexplicably determined that young people at that time were interested in "cooperation rather than competition." I always take market research with a ton of salt, but it did spark the idea of having the two players work towards the same goal.
Perhaps the Cold War fears of the time made young people tend towards cooperation rather than conflict. A separate high score list for team play, where both players shared a total score, promoted the feeling of cooperation in Rip Off.
Of course, co-op would go on to become a major feature in video games in the future. More than 1800 co-op games are in our database today, and that number will surely grow as we find more hidden gems from the past and new co-op titles are released every month. Rip Off was among the first titles to embrace teamwork and collaboration in gameplay. Its impressive AI was certainly influential, and the "protect the fuel" gameplay hook is much like the survival modes common in many games today. The hundreds of co-op titles that followed Rip Off owe much to this fine example of a Co-Op Classic.