Conversion of later material

[korgoth]

I was thinking about conversion of later material (Classic, 1E; I guess even 2E if I were so inclined, which I'm probably not) to OD&D. OD&D actually seems like a possible meeting point of the later versions: mechanics similar to Classic but many of the spells and critters found in 1E (in the supplements, that is).

Since OD&D assumes a d6 HD (assuming one is not using the variable HD rules) for monsters, it seems like if you were going to use a published adventure from Classic or 1E you would subtract 1 HP per HD to account for a d6 rather than a d8 base.

Any other insights into converting the later material?

[coffee]

I'd say that's a good start.

1st Ed AD&D was where the scale of things started creeping up. The PCs had more hit points (Fighters had a D10) which fit nicely in with the d8 for monsters. So I think I'd look closely at the levels suggested for adventures. If it says it's for 5-9th level characters, I'd interpret that as 6-10th in OD&D. (at least until I had tried a few).

As far as other things go, such as spells and items, I'd say go over them with an eye to reducing the restrictions (and complexity!). OD&D was wide open; AD&D started to add the "legalese" to things like spell and item descriptions.

Anyway, there's my $0.02.

[Stonegiant]

The monsters of the MM in 1st edition really don't have that much conversion work to do (none have an AC worst than 9, and the numbers of HD are almost identical to their OD&D counterparts) Remember the MM was published first and was intended to be used with OD&D until the rest of AD&D 1st edition came out.

[Finarvyn]

Stonegiant has a good point. Those of us who were playing back then used the AD&D Monster Manual with our OD&D game because we didn't have any other options. In general, it works just fine.

Weapon damage is a little beefed up in AD&D, but not enough to be a problem overall. Especially if you use AD&D weapon damage in your OD&D game, because it tends to balance out if both players and monsters have larger damage totals.

I don't usually bother to adjust the HD numbers, either. Just play 'em as written in the MM.

The AC 9 versus AC 10 issue is actually a non-issue for most monsters; at most you're off by 1.

korgoth said:

Since OD&D assumes a d6 HD (assuming one is not using the variable HD rules) for monsters, it seems like if you were going to use a published adventure from Classic or 1E you would subtract 1 HP per HD to account for a d6 rather than a d8 base.

If you really want to convert HD, it's not that hard. As I said, I tend not to bother but it's a simple process. A d4 averages at 2.5, a d6 averages 3.5, d8 is 4.5, d10 is 5.5, and a d12 is 6.5 so you could use those numbers to create a number of hit dice that should give similar hit point totals. All you need to do is multiply the number of AD&D hit dice by the average points per dX and divide by the number of points of a d6. In addition, each 0.17 of a hit die represents 1/6 of a hit die or could be expressed as a +1 to the hit point total.

In other words, if a monster has 4 HD that are d8 in AD&D, you could simply do this:

4 * (4.5/3.5) = 5.14 = 5 1/6

which means that it would be roughly 5+1 HD if d6 are used.

For another example, if a monster has 13 HD that are d10 in AD&D, you could simply do this:

13 * (5.5/3.5) = 20.43 = 20 3/6

which means that it would be roughly 20+3 HD if d6 are used.

Not sure if it's worth the effort, but it would generate d6 hit dice with similar hit point totals. Also, you'll note that it generates hit dice numbers which are a lot larger. AD&D hit points tend to be larger as damage gets larger and AD&D tends to top-out at 20th level whereas OD&D caps out closer to 12th. Because of the scaling factor, you could go back and multiply each HD total by 12/20, or 0.6 to reflect the lower cap.

In that case, my first example of 5+1 actually scales down to something closer to 3 HD while my second example of 20+3 is closer to 12+2 HD. In other words, the larger HD type and the scaling factor actually tend to cancel each other out.

Bottom line: Stay with the same number of HD and it should work out just fine. ;D

[korgoth]

admin said:

Bottom line: Stay with the same number of HD and it should work out just fine. ;D

I agree. I just meant that if a 4 HD monster in a module for Classic or 1E is listed with, for example, 21 hp, if you are using a d6 base instead of d8 for HD you might want to adjust the hp down to (21-4=) 17 hp.