In its most basic sense, Rugby is a full contact collision field sport that is essentially socially approved simulated tribal warfare. It is played with 15 players on each team and over 2 halves, each approximating 40minutes depending on injuries. From a task specificity perspective (energy system stress, physical collisions, force output requirements, running velocities, technical/tactical/strategic components, etc.), it falls somewhere on a spectrum in between American Football and Australian Rules Football while of course varying in similarity to each end of said spectrum by positional demands.