NFL Street 2 Designer Diary #2

Taking the NFL Street Football Engine for a Ride

By Josh Johnson
Lead Gameplay Programmer, EA Redwood Shores

In NFL Street 2, we added six all-new street events that give you a number of things to do besides playing a seven-on-seven football game. One of the choices we made when designing the street events was to reuse the football engine from our main game mode. That way, once you understand how to play NFL Street, learning how to play a street event is simple. We use the same controller configuration throughout all game modes, so once you learn how to pass the ball in one mode, you can do it in any mode.

Crush the Carrier

This is the game everyone played with their friends when they wanted to goof around. One guy gets the ball, and everyone else tries to catch him to knock the ball loose. Whoever collects the loose ball gets the opportunity to rack up points while stylin' around the field. The longer you have the ball, the more points you can get. Of course, if you're skilled enough on defense to get to the ball carrier before the other guys, you can force the fumble and boost your own score. Once we created an initial version of crush the carrier, we had several testers, designers, and developers play around with it. We discovered a number of flaws in the pursuit logic the artificial intelligence was using to chase down the ball carrier. In a regular football game, the defense makes decisions to keep the ball carrier from getting in to the end zone. In crush the carrier, the ball carrier doesn't care about going downfield. He simply tries to get away from everyone the best he can, no matter what direction that takes him. The defensive-pursuit logic had to take that into account, and it had to forget about preventing touchdowns.

Jump Ball Battle

Now you have an opportunity to master the art of catching the ball. You and three other receivers are fighting for three footballs launched into the air simultaneously. You have to be able to cut off the other guys and time your catch just right to take the lead. Initially, however, the AI receivers weren't getting to the ball before a human user. We discovered that the receivers, who had to use some defensive logic to know how to beat fellow receivers to the ball, were sometimes playing over the other receivers...as if they could wait and make a tackle. We fixed that and found that our AI had become excruciatingly difficult to beat. It was just too good at knowing where to go to make the pick. So, the biggest feat we accomplished with jump ball battle was dumbing down the AI enough to make it fun on the easy and normal difficulty settings.

Open Field Showdown

You can play this as a one-on-one or two-on-two game. Each play alternates which side starts with the ball. The goal of the offense is to get in to the end zone in one play, while the defense tries to make the stop. In a one-on-one game, the ball carrier has to outmaneuver his opponent with no help from anyone. In a two-on-two game, the offense can pitch the ball back and forth and/or block for the ball carrier. The hardest thing to overcome in this game was the AI's pursuit logic. The ball carrier starts 20 yards from the end zone, while the defense starts inside the end zone. That doesn't give the defense much time or room to figure out how to approach the ball carrier. We went through a number of revisions to the pursuit logic before we were happy with how competitive the AI players could be. Our testing department was pretty good at identifying "money" plays that would stump the AI defense. Once we knew where the holes were, we were able to identify what the AI needed to do to pose a real threat.

Two-Minute Challenge

This game requires you to become both a master of finding the open receiver and a master of being able to cover the other team's receivers. The offense has a QB and two wide receivers, and the defense has two defensive backs. On offense, you have two minutes to score as many points as possible, but all you can do is pass the ball to one of your receivers. Once your two minutes are up, you switch sides, and the clock resets for the other team. The major issue creating this game was making the AI defend against the pass in a challenging manner. Since we added wall catches to NFL Street 2, the receivers have the advantage of being able to leap off of walls to catch the ball well before it reaches the original target location. We had to make sure the defensive backs were smart enough to climb the walls themselves to pick off the ball. "Smart enough" is subjective, and it has to consider the difficulty setting specified by the user. After weeks of tuning, we reached a level that makes sure the defense keeps the passing game interesting for the human user.

Let the Trash Talk Begin

In addition to the modes listed above, we have also added four-on-four and quick strike to the street events. In the end, our little football engine proved to be quite versatile. We even took some of the tricks we learned from the street events and used that knowledge to make the regular seven-on-seven game better. Personally, I've spent a silly amount of time playing each of these events against my coworkers. The amount of smack talk that has come out of a simple one-on-one open field showdown may never be topped by any other game...ever.