The idea, in a nutshell, is to simplify experience point distribution for busy game masters,
and still provide a decent rate of progression.
The Dungeon Masters Guide provides an alternative, a flat rate of 300xp per level, so that is
what I have gone with. I total the party level, including various NPC party members, and divide
it by the total number, multiply this value by 300, and that is that.
Enter your average party level, and press the button:
Yes, I know this is a horrific simplification of the XP awards system, but it seems to work for us (so far). It most strongly rewards the people that show up regularly.
The biggest downside is that characters that are down in experience due to dying or coming in late stay behind the leaders, without a lot of opportunity to catch up.