Gary Gygax was wrong.
…when he said this.

After playing in Luke Gearing’s OD&D game for about a year I really began to love the simplicity of making monsters worth 100XP per Hit Die. It’s actually so simple, why did we ever move away from it?
This is especially true in my games, where my Wizardry, Final Fantasy, Dragon Quest brain equates the primary way you level up to be killing monsters. Gold is, of course, worth more, and I write my material with that assumption and that work, but for my own system? My own games? I need not be 100% beholden to that. I like a fighty D&D game where the players take on big crazy monsters. I have all these fucking monster miniatures for a reason; I’d like to goddamn use them!
But after a while we sort of started to see the flaw in the 100xp for HD. We were doing a lot of stuff up on Floor 1 of the megadungeon and killing all sorts of guys, some of whom were worth a lot of XP, and we are sort of high level–we’re talking 5, 6, 7th level fighters and magic users here, and with magic items coming out of our ass. It was trivially easy for us to nuke a party of 3HD monsters and move on with our day.
So the new rule was instituted that The Formula suggested even in OD&D would be used: monster HD x 100 divided by player level or whatever it is. We all rapidly saw Our Gains go down the drain.
I was never happy with this formula. For one thing the dungeon level doesn’t necessarily equate to what HD the monsters are, so this math really starts to fall apart depending on how much you’re doing outside of that box. For two, it only encourages you to go further into the dungeon, not to fight larger foes.
Here’s my proposal:
Each monster is worth a baseline of 100XP per HD. This is thrown into a big pool.
So the players fight let’s say 5 3HD monsters. 300 x 5 is 1500xp. That’s the pool. Now we look at the players. The party is a 2nd level MU, a 4th level fighter, and a 3rd level thief. What we want to do is compare all of the player HD to the monster HD, and determine what share each player should get. This is the XP Cap of each player. Notably, we do not yet divide XP.
In this situation, the thief is equal to the monsters’ HD and so is entitled to a full share of XP. The Fighter is at 4:3 and so is entitled to 75%. The Magic User is level 2 and at 2:4 and thus is entitled to 200% share.
What this means is that each player takes the 500xp they are entitled to and then multiplies by their %. So the MU actually earns up to 1000xp from this encounter. The thief earns 500xp. The Fighter earns only 375xp.
But wait: that seems like a lot so we need one more step. Each participant takes their XP from the pool from lowest to highest. So the Fighter first earns 375 XP, leaving 1125XP. Now we subtract the Thief’s 500xp leaving only 625 for the magic user. Less than their weighed 1000xp would have been, but still more than they would have earned otherwise.
What this does is reward fighting a monster bigger than you but not necessarily encourage it as there is an upper limit to how much you’re going to earn. This group of orcs can only ever reward 1500xp. But in this formula, no XP is ever “lost.”
Of course, this is also a lot of math. So if your party would rather not fuck around with it, you can just go with 100xp per HD. Or, idk, less, like Gary did, which carried over into B/X and AD&D. Maybe he was right after all, or maybe they wanted to discourage fighting by removing it from the XP progression. Who knows.
(Also we should be adding multipliers based on certain monster special abilities, like 2e, but that’s another topic.)

















