How the design coaches for you
The type of target changes the behavior — big goals pull for finishing, mini-goals for combination play, gates for dribbling and outplaying, end zones for penetration. Rules do the same: a touch limit forces scanning and quicker passing, a minimum-passes rule builds composure, an incentive like a bonus for switching play rewards a behavior while still leaving the player free to choose. The environment teaches, so you don't have to lecture.
The principle I hold onto
Their best line is to modify the game as little as necessary but as much as needed. That restraint matters, because it's easy to pile on so many rules that the game stops looking like football and starts looking like a puzzle. I'd rather change one thing, watch what emerges, and adjust — because I'm designing an environment for players to solve, not a set of hoops to jump through. When the design is right, my job shrinks to observing and asking a good question, which is exactly where I want to be.