Minion Wars

We progressed up to Kurast! Sit back and relaxed game it was indeed.
Our friend at level 1 found it hard to join us who were at level 16. It appears that
a low level character earns almost no XP for kills when he is part of a a much higher level party.

Here is the reason why:

Exp gained = Monster's Exp * Exp fraction
Exp fraction = Your level / (total of all party member levels)

So the Exp fraction for our level 1 player was (1/1+16+16+16), only 2% of what it was when he started playing solo!! See this website.