Tag rugby is an adapted version of contact for younger players,It involves having to wear a velcro belt witth two tags on either side of the players waist, when a tag is pulled from the player this counts as a tackle. The reasons for playing tag is its safe for beginners, no contact involved helps to focus on using space in attack and passing.
Well obviously you defend by touching (generally with two hands) rather than tackling. There are no set rules, but some modifications are more common than others. A few are (1) any ball which touches the ground (ie a dropped pass) is a turnover, even if it goes backwards; (2) you can't generally use kicking attacks like grubbers or up-and-unders; (3) after a touch defenders have to give the attackers three metres off the ball rather than lining up on it; (4) if the dummy half (the player playing the ball immediately after the touch) tries to advance and is touched before passing it is a turnover; and (5) some competitions will limit the number of touches a team is allowed (typically 6), turning it over after that number. Really, in may ways touch-rugby is more like the League game than the Union.
In tag you have a Velcro belt with tags on it , instead of tackling the player you pullbthe tag off.
Tag Rugby is used for a younger age group that have mainly only just started playing and are getting to grips with the sport, After so many years you move onto Contact Rugby. This is where they start learning to tackle. As years progress, more things will be added into the game (scrums, Lineouts etc.) until you reach full-contact which is for the more advanced players that have an understanding. Hope this helps :)
tag Rugby involves just touching the other person. Regular rugby is a full contact sport.
