Converting NPCs from AD&D to GURPS

[Valadrim]

I know I tend to do more work then is really necessary, but for my perpetually in the works Birthright game I am trying to establish a metric for converting NPCs.

I originally thought to simply port over the stats. I.e. 12 strength = 12 strength. But I suspect the upper ends are different. In AD&D a Dex of 18 is remarkable, but in GURPS it is almost stupidly dexterous making the NPC mindblowingly talented at every dex based skill.

So here is what I am thinking. Ability scores 2-14 convert at a one to one ratio, scores 15-16 lose one point in the conversion, and scores of 17-18 lose two points in the conversion.

Charisma scores relative to IQ along with concept will inform whether to add GURPS Charisma (an how much). Wisdom relative to Intelligence along with concept will inform me if I should provide bumps (or reductions) to Per and Will.

HT will be capped at 14 unless there is a good reason to do something else.

What do you think? I could scrap direct conversion all together, and build everyone up from concept, but I don't think that will be necessary. Can I have your thoughts?

[Blind Mapmaker]

I would convert 10 to 12 straight and drop one point for 13 to 15 and two for 16 to 19. All attributes below 7 should be raised to 7 unless there is a very good reason not to. 7 to 8 should add two points and 9 should add one. A good cut-off point for high attributes of any kind should be 15 unless the character in question is really important (like a Birthright noble or office-holder).

Also try to think outside the box. Advantages like Combat Reflexes are certainly assumed to be part of a D&D attribute score. If you like use the exact point cost to convert part of the points of the adjusted attribute to advantages.

[Kuroshima]

Convert by concept, not mechanically. The assumptions on both systems are very very different.

if you're dead set into making a mechanical conversion, 3.X, I would convert using the attribute bonus, so Dex 12 would convert to DX 11. ST might be treated differently, and converted 1 to 1. Now, AD&D had strange bonus scales from attributes IIRC, meaning that this is even harder, specially when you consider Str 18/XX. Still, the rationale stands. For ST, use 10+damage bonus. For Dex, use AC bonus. For Con, use the bonus to disease/poison save as the HT bonus (not the HP bonus). For Int, I really don't remember the bonuses it game well enough. Same for Wis and Cha.

There's only one reason for mechanical conversion, and it's NPCs were you only have the class level and stats, with no background, and still, it's quite better to see what concept they embody before starting the conversion.

[Turhan's Bey Company]

Originally Posted by Valadrim

I could scrap direct conversion all together, and build everyone up from concept

This. One can come up with a comforting mechanism to convert primary attributes because they're more or less on the same scale, but I find that it's a bit of an illusion, since GURPS stats have more profound implications than D&D ones. Moreover, things start to get whacky when you move into conversion of levels, feats, proficiencies, and D&D-flavored skills into advantages and GURPS-flavored skills, where there's little or nothing in the way of correspondence. You're going to have to do most of it by concept anyway, so you may as well do the whole thing that way.

[whswhs]

In terms of sheer probabilities, each +1 to a D&D stat is +5% to success chances. That isn't true with GURPS, which uses a bell curve. Going by probabilities, I would get this, roughly:

GURPS D&D
5 1
6 2
7 4
8 6
9 8
10 10
11 13
12 15
13 17
14 18
15 19
16 20

Bill Stoddard

[simulatoralive]

I always got reasonable results converting strength based on lifting capacity. For large monsters, I use the guidelines from the Growth Advantage to determine a minimum ST based on size and then tweak from there. Most large monsters become unbelievably deadly. Hehe.

Levels should translate into higher skill levels, in my opinion. Pick a few core skills, based on class, and increase them accordingly. Or, add a number of character points for each level and allocate them to those core skills.

Sometimes a hybrid method that mixes the mechanical approach and the concept approach is nice. This is what I usually do.

Pick a few reasonable rules of thumb for basic stuff and add flavor as you convert. Customize and make the character better than it was in AD&D. Make it your own.

[Rasputin]

Funny, I was coming up with something for this. The pre-3e editions of the game were sparse for stats for NPCs; for 3e and later, you convert the bonus. I assigned stats from a table for older NPCs, which were keyed to be below a DF character at 1st level.

The basic idea, in the end, is that every class is a bang skill, specifically one in Dungeon Fantasy. Weapons other than those listed in the DF bang skill go up as another skill, and the classes get a few common advantages and disadvantages (all barbarians get Great Rage from DF11 since that handles their 3e Rage ability; clerics get True Faith (Turning); monks get Catfall; you get the idea). The idea is to be able to convert an older module (I was looking at Temple of Elemental Evil) almost on the fly, though I don't think I've done that.

If you want to convert every little feat and skill, that's your headache. I'm going more for a 12th level Monk knows Martial Artist! at DX+3 and you handwave most of the details as, "Yeah, he should be able to do that."

[Phaelen Bleux]

I have always converted at a 2:1 ratio, i.e.,

11-12 = +1 in GURPS
13-14 = +2
15-16 = +3
17-18 = +4
18 + % (for ST) = 15

[Gorkamorka]

I'm currently playing with converting ADnD Dark Sun into GURPS 4th. And my take on it is to go for the feel not the hard conversion. I just ran into far bigger problems then I wanted to deal with to convert ADnD to GURPS directly. The main one being how much damage can a character handle. GURPS is at its base a deadly system and ADnD is not. Both can be converted to the other, but I feel it's easier just to go for the feel of things rather then do that conversion.

[Snaps]

A lot depends on how you plan on setting up your world and what points scale you want to use.

Think of the best warrior in your setting. Do you see this guy as a 300 point character? 500 points? 1000 points?

This will determine a lot about how you should convert over the D&D characters.

For me when I've done it in the past I shot for 10th level characters being about 300 points and 20th level characters being about 500.

I think an easy conversion is to just look at their Modifier for their D&D Stat. 11 for a +1, 13 for a +3 and 15 for a +5 sounds about right to me. At least for DX and IQ. You might be able to convert ST and HT straight over.

Still, you are going to get way better results by just doing it by points. Toughness, High Pain Threshold, etc are going to go a lot farther than +1 or +2 HT.

And keep in mind that converting some things over will just end up being a lot of points. Shardminds for example are immortal and can speak to any intelligent creature. That's a freebie in D&D, but not in GURPS.