The field of play is 110y by 65y, with 20y end zones. The uprights are on the goal line and both rulebooks in Canada (there are only 2) use 3 downs. We also use 12 players.
Some leagues use 4 downs if they feel that is benefits them, such as a house league program where kids might not play in rep leagues.
The signals are a bit different but the principles are the same. In addition, penalty application is different.
Three down football is amazing! Visit
http://www.13thman.com some day!
Regards,
Mike