D&D Next Monsters: Part 9: XP Curves & KpL...

While this blog does not contain material published by Wizards of the Coast it does contain materials summarized and extrapolated from the D&D Next playtest packets. By continuing to read this blog you are consenting to the terms of the Wizards online playtest agreement, which you can view at dndnext.com.

Surf looks at monster XP progression....

So +Jonathan Black asked +Mike Mearls about the discrepancies between low, mid and high level character progression. Specifically "Why does it take more xp to go from 10 to 11 than 11 to 12?". Mike didn't answer, but this raised some questions about monster XP progression in my mind, so I decided to take a look...

 

PC Progression

Level	XP	Difference
1	0	0
2	250	250
3	950	700
4	2,250	1,300
5	4,750	2,500
6	9,500	4,750
7	16,000	6,500
8	25,000	9,000
9	38,000	13,000
10	56,000	18,000
11	77,000	21,000
12	96,000	19,000
13	120,000	24,000
14	150,000	30,000
15	190,000	40,000
16	230,000	40,000
17	280,000	50,000
18	330,000	50,000
19	390,000	60,000
20	460,000	70,000

First up let's take a look at what Jonathan is talking about. Let's take the PC progression table and subtract the previous level's value from each level. This gives us the XP a character needs to gain to go up to the next level.

Now to gain a level we expect that we should need to gain more XP than we needed to gain last level. Or at least the same. But not less. Now take a look at the differences at levels 11 & 12.

The only explanation for this is human error. I believe this is a simple transposition mistake. If we swap the two values around then everything is perfect. This is the kind of think I'd expect Wizards of the Coast to fix quietly.

Swapping these two values works perfectly. In mathematical terms there isn't much real impact and it's probably not worth the headache of getting your whole group to understand the issue and agree that XP to reach level 11 should be 75,000 rather than 77,000. But if you are keen that's the only change required.

Of course, working through this got the old mental cogs turning...

 

PC Progression vs Monster XP

Looking at PC progression got me thinking about the relationship between it and monster-at-level XP values. There's a relationship between the two, regardless of how loosely Wizards of the Coast have defined it. Obviously the PC progression chart helps us here, as does the Average column of the encounter design table (which is essentially the XP for one Average monster for that level). One of the design concepts of D&D Next also tells us what to expect. That is "...fast advancement at lower levels with more gradual advancement at mid- and high levels".

 

Monster XP Curve

Simply graphing the Average monster XP by level shows us that it's all over the place. I'd say "quite out of whack at higher levels". The trendline on the graph shows the kind of progression I'd expect.

What we see is that after level 11 there's a lot of XP that's just way higher than we'd expect. One could argue that this doesn't matter because the encounter math is built on the assumption that monster XP values use the same table. And running some quick pivots show that's the case.

Level	Easy	Average	Tough
1	10	20	40
2	40	60	110
3	70	100	200
4	110	160	320
5	150	230	460
6	220	330	650
7	290	440	880
8	400	600	1,200
9	510	770	1,500
10	670	1,000	2,000
11	850	1,300	2,600
12	1,080	1,600	3,300
13	1,400	2,100	4,100
14	1,700	2,600	5,200
15	2,200	3,400	6,700
16	2,900	4,300	8,600
17	3,600	5,500	10,900
18	4,700	7,000	14,000
19	5,900	8,900	17,700
20	7,500	11,300	22,500

And yet this argument misses something important - the impact to PC progression. These higher XP rewards, and higher associated encounter XP budgets, mean that PCs level up with fewer fights than if the correct values were being used.

When we are levelling up too quickly we feel that the game is too easy. So these over-curve XP values likely play a part in the feeling that D&D Next combats are too easy at mid and high level. Not that they are the only factor.

Regardless of whether it's necessary, it is pretty easy to determine the "right" values. We just add an extra column to our graph, copy the current values into it and then adjust them until each point sits on our trendline. We can even sprinkle in some of the usual RPG industry "rounding magic" to make the final table a bit more palatable to the human mind (people like to see zeros on the ends of longer numbers).

Which gives us a handy new encounter budget/monster XP chart.

Now, let's see if it proves useful...

 

Kills Per Level

If we subtract the XP needed to reach the next level from the XP needed to reach this level and divide the result by the XP value of an Average monster of this level we learn the Kills per Level (aka Kills/Level aka KpL) for this level. We can trivially do this for every level and then graph the result.

And the result is really interesting!

Yes, the values are scattered. And yes, we can correct this pretty easily simply by using our new Encounter/Monster XP table (see the "Revised" graph). But what's interesting is the curve! Wizards of the Coast seem to have decided that from level 10 we need to have far fewer fights each level. I'm guessing that's because they didn't plan to release many mid- or high-level creatures during the playtest and only planned to get a feel for what the epic tier of play was like.

And I reckon this is a factor in the feeling that the higher levels of play are too easy.

 

Correcting It...

Level	Curved Tail	Plateau
1	0	0
2	250	250
3	1,100	1,100
4	3,100	3,100
5	6,500	6,500
6	11,800	11,700
7	19,700	19,300
8	30,600	29,800
9	45,600	44,200
10	64,800	62,600
11	89,600	86,400
12	121,000	117,000
13	159,000	155,000
14	207,000	204,000
15	266,000	265,000
16	341,000	344,000
17	433,000	443,000
18	550,000	570,000
19	697,000	732,000
20	883,000	936,000

There are pretty much two options for correcting this. The first is simple, we halve the XP budget and XP value for encounters and creatures over level 10.

The second option is not something I'd ordinarily recommend, but the more I look at it the more convinced I am that it's the right way to go. It's an option you'd have to sell to your group - updating the PC progression table. Generally I prefer options the DM can silently use behind the scenes, but if PC progression is at fault then that is what is most appropriate to correct as other corrections will have side effects. Some of which won't be immediately obvious.

If we do this we need to decide how we want our progression to look. For my money I like a "curved tail" curve that starts like the current curve, it curves up to 25KpL at level 8, from there gently curves down to 21 KpL at level 20. The other option I'll present is a "plateau" curve which also starts similarly, curving up to 24 KpL at level 8, from there ever so gently dropping down to 23KpL at level 20. Again, I applied a little rounding to make the final numbers more natural for humans.

Then again, none of this matters if you don't use the PC progression table... Like my own group. When the DM simply decides how often everyone levels up this whole article become a moot point.

But it was an interesting moot point...

 

 

Check back next week for the Part 10: Final Packet Analysis...