This diagram shows a basic lacrosse positions layout. There are many different formations that are utilized, but this will give you a general idea of where they line up.
Lacrosse Positions descriptions
Midfielders (also commonly known as Middy's) roam the entire field. They should typically be your best all around athletes and they need to be in very good condition because they cover an enormous area. Middy's need to be good defenders, and they need to be able to be strong on the attack, but their real value is in their ability to transition the ball from the defensive to the offensive ends of the field. Middy's are the real work horses of the lacrosse team.
Attackmen typically spend their entire lives in the opponents end of the field. They cannot cross the midfield line during play unless they are replaced by a middy, so that there are always at least 3 players in the offensive end. Attackmen need to be extremely agile and excellent stick handlers. Good attackmen should be equally capable with either hand. The real test of a great attackmen is not just how adept they are at scoring goals, but how well do they pass (feed) the open man to set up the goal. Great attackmen usually also have large numbers of assists as well as goals.
Defensemen (Long Poles) are the enforcers. They are the players who are capable of dictating to the opponents attack where they can go, and where they will be punished for going. They need to be very physical, but still extremely agile. They utilize much longer sticks up to nearly 60" long which allow them to disrupt the opponents attack. Great defensemen need to have exceptional feet. Position on the field is the key to being a great defender. Cutting off the opponents angles to the goal is critical. The longpole will generally abuse the enemy with a barrage of checks from the longer pole and work them selves between the attacker and the goal, all the while working to dislodge or intercept the ball. Longpoles like the attackmen must stay on the defensive half of the field unless replaced by a middy. The defenders job is often also to "Clear" the ball down the field after a turnover out of the defensive zone. One of the most exciting plays is when a longpole runs down the field and a middy stays back to allow the longpole to run all the way to the opponents end and shoot or pass to a fellow attacking player. It is lacrosse's version of running the floor on a fast break in basketball, and it is thrilling.
Goaltenders (Goalies) of all the lacrosse positions are probably the most important on the team. No one is under as much pressure to be perfect as the goalie. They are required to stand in front of a 100 plus mile per hour missile that is the size of a tennis ball but weighs much more, and is hard rubber like a hockey puck. Believe me when a ball gets through the armer it will leave bumps, bruises, and welts. Goalies need to be very courageous. They are going to have to endure pain for sure. If they have a low pain threshold then they tend to get gun shy and start ducking. Many people believe that Goalies should be large to take up space in front of the goal, clearly the more space you can cover the harder it is for the enemy to find a hole, but in my opinion it is far more important to be agile like a short stop or catcher with lightening hand eye coordination and reflexes. I have seen very small goalies with quick reflexes play great in goal. The goalie also needs to be a smart player as he usually will be the one barking orders to the defense. He has the best vision to who has the ball. You can overcome a lot of adversity with a great goaltender.