Think of lacrosse as ice hockey but make the following substitutions
1) Hard rubber ball 2.5" in diameter instead of puck
2) Field for rink
3) Stick with a net on the end rather than a stick with a blade
4) You can carry the ball with the net on the stick
5) When you have the ball the defenseman can whack the hell out of you with his stick
The rest is about the same - body checks, etc. and just a helmet, small shoulderpads and heavy gloves. Goalies get a cup. A good H.S. player can shoot the ball at about 80-90 mph and God help you when that ball hits.
With respect to soccer players who are also great athletes, there is absolutely no comparision in violence.
Was not always the case. Many, many years ago, some of the hits and unsportmanlike tackles in soccer were brutal. FIFA has done much over the years to clean up the bad fouls.
I remember watching some of the World Cup matches in 1966 when my dad was stationed in England. The superstars were getting mugged on a regular basis in every game and few red cards were issued. Some of those tackles would get a player tossed and suspended theses days.
The left-half for England was Nobby Stiles. Very few skills but a very physical defender.