Two important rule changes in changing American game from rugby were to introduce line of scrimmage instead of scrummage and to establish down-and-distance rules.
American game-ஐ rugby-ல இருந்து வேற மாதிரி மாத்தினதுல ரெண்டு முக்கியமான rule changes - scrummage-க்கு பதிலா line of scrimmage-ஐ introduce பண்ணது, down-and-distance rules-ஐ establish பண்ணது.