Sunday, 31 May 2015

My Classic D&D Monster XP System

I base my XP off the OD&D 100/hd, but then I bring in the 3e idea of +2 levels = x2 XP, ie:

hd XP
0.5 50
(1-1 80)
1 100
(1+1 125)
2 200
3 300
4 400
5 600
6 800
7 1200
8 1600
9 2400
10 3000
+1 +1000

Special abilities typical add +50% or +100% XP, eg an MU19 might garner 12000x2=24000 XP, where a Clr-19 Ftr-19 Thf-19 garners 12000, or 18000 if they have loads of magic items. Big dumb unintelligent critters may earn only 50% as much XP.

This seems to work very well IME, 1600 XP for a hill giant equals 16 orcs and that looks about right.


  1. Is there a reason you only start doubling every other level after level 2 (i.e. 2HD is 200 XP rather than 150XP)?

    I tried this system but found that at high levels +2HD makes a monster not that much harder. What I ended up with is on my blog.

    1. It's the OD&D 100 XP/hd system mixed with the 3e +2 CR = x2 XP system. I find it works ok to give x2 XP for +2 hd up through 9 hd then a flat +1000/hd thereafter. I don't use XP for 3e-5e 'challenge' encounter-building and I like it that big monsters are more generously rewarded.

    2. I see you say "Killing a single high level monster gives you inordinate amounts of XP, so should probably be reduced down to only 25 times as much (in line with how hard they are). " - which fits pretty close to my XP spread, 9 hd gives 24 times as much as 1 hd.

  2. I see – I hadn’t spotted that it went to a flat system after Lvl 9. Because of that, and of the doubling from 1HD to 2HD, you have a very similar rate overall to the one I linked to. There are big differences in places – e.g. between 8HD and 10HD in my system it goes up by 50% and in yours it doubles – but it’s the overall picture that matters and they’re so similar I doubt players would notice the difference! It’s far more important that you’re giving out four times as much as me - I think in that regard the players would prefer your system :-(

    In my system Explore I double XP every other level right the way through from Level 1 to the top, and I like the consistency of that.

    1. Yes, the structures are very similar, and very like the 3e CR/XP system up through level/CR 9. The amount of XP I give out has the result that PCs in my Mentzer Classic game level up every 3-4 sessions, which is the stated intent in both Moldvay & Mentzer, but only achievable via those systems' RAW if the PCs gain huge amounts of gold at 1 gp=1 XP. I don't particularly like the necessity of huge loot drops, and in practice the published adventures I've been running rarely give out anything like enough loot to support that sort of advancement rate. Whereas using my monster XP system (plus Exploration XP, which is typically 100-300 XP per PC per session) the PCs have been getting typically ca 800 XP per session. After 9 sessions the two PCs present in every session now have a bit over 8000 XP (F3 8259, MU3 8109) which I'm happy with; with strict RAW they might still be under 1000 XP.

    2. F4 8259 - she hit level 4 after last session. :)

  3. You're basing your view on actual play? My god - what's the world coming to!

    1. I don't see much point developing material that's not going to be used in play. Sometimes I get a shock reading theorycrafting threads when I realise people are pontificating confidently on games they have no intention of ever playing!