yeah, the first who clicks on the item gets it ^^ you have to be quick

your position between front,middle and back are their position face to monsters

in front, you're in front ^^ so you get hit more often ( you go front usually when you're a tanker with a good armor and life )
in back, you get lass damage then others ( great for caster with huge mana and ver low life , who can cast and heal the tankers

)
in middle, between those two ^^
noticed that it depends where the differents chars are
if you're all back, it is the same as you were all front ^^