First, here is a succinct primer on the game of Rugby (Union): http://www.artofmanliness.com/2009/03/10/rugby-basics/
Second, I can assure you that there are dozens of set plays in rugby that may not be apparent to rugby novices because there are no timeouts (except for serious injuries and half-time) and the set plays often called while play is in motion. The are a multitude of set plays whenever the ball is put back into play after a stop in the action (i.e., kick-offs, penalty kicks, line-outs, and scrums). There are also set plays off of rucks, mauls, kicks, and tackles, all of which occur when the ball is in play. Watch a few videos of Johnny Sexton, who is arguably the greatest fly-half (No, 10) to play the game for Ireland and beyond. (The fly-half is roughly the equivalent of the quarterback in American football.) Much of what you will see are set plays with a touch of improvisation to cover the “what if” situation. Here are some examples:
https://www.youtube.com/watch?v=-IU2tpBfM9c
https://www.youtube.com/watch?v=0IIW0Hf7-UQ
https://www.youtube.com/watch?v=CryxUGgdr-I
Third,(and I say this with tongue in cheek — sort of), the average American football player can't even spell “Alabama” or “Florida” let alone play an entire game without a stoppage after each down and an insufferable number of timeouts so that someone smarter can tell them what to do.
Interesting. Thanks!