The Foresight of My Father’s AD&D 1st Edition House Rules

AD&D 1st Edition Dungeon Master's Guide CoverI inherited my passion for roleplaying games from my father. He played the first edition of Advanced Dungeons & Dragons with a roleplaying group based in Sydney. When I was in my teens, he Dungeon Mastered my first games. Many years on we’re playing the original 1st Edition AD&D scenario, The Temple of Elemental Evil, using the original 1st Ed rules. Sort of. You see, I inherited my 1st Ed books from my dad, who carefully imported them from the US in 1980 (they weren’t available locally for a very long time) and made many notes and house rules as he tromped through dungeons through the ‘80s and ’90s. It has struck all of us as being interesting to see the thoughts of people playing the same game over 30 years ago…

What follows is a summary of the house rules that my father devised to ‘fix’ what he saw as broken in the AD&D system. A lot of what he came up with would later become official rules (THAC0 for instance) much later after he first scribbled them down in the margins of his books.

Balanced and Mathematically Valid XP Tables

The modified tables are now available as a pdf

I love the XP system in AD&D. The approximate doubling of XP allows elegant multiclassing rules, and the separate tables for each class allow interesting balancing.

The fact is, however, the XP tables in the original AD&D were borked. They were poorly balanced, and mathematically, well, stupid. Here iss a plot of the original 1st Ed AD&D XP tables:


…yeah. D&D wasn’t written by maths nerds. When the Druid hits level 12, the poor Paladin is still on level 8. Magic-Users also get it pretty easy for most of their career. The classes with god powers spells need less XP for many levels than Paladins, Rangers, and Monks. There’s not much sense here, and it is certainly very unbalanced.

But I am a maths nerd, and more importantly my dad back in the ‘80s was also a maths nerd, so lets see how he fixed these level progressions:


Paladins are still a bit behind (they are pretty powerful in 1st Ed), but not so bad. The Magic-User’s XP requirements are closer to their actual power. Druids aren’t broken. All by applying the concept of the XP tables (doubling each level) and actually doing it with some sense of mathematical correctness.

Mathematically Valid Spell Tables

The modified tables are now available as a pdf

The spell tables suffer the same problem as the XP tables: no sense. Have a look at this:


In addition to a very favourable XP table, Druids got more spells, faster, than any other class. Go figure. There’s also some weird halts in spell progressions.


That’s more like it. Astute readers will note that this progression (1/3/5/etc) is exactly the same as 3rd Edition. The Druid quirk at level 12 is because the druid XP table stops at 14, and the modifications try not to change final spell numbers, just initial acquisition levels.

Bonus Spells for Magic-Users

By the 1st Edition rules, only Clerics get bonus spells for high Wis. Magic-Users and Illusionists get nothing. Druids are vague. This means your poor level 1 Magic-User has a whopping… ONE spell. Yup.

Neatly pencilled next to the bonus spell table is this sentence: “Use for Magic Users also, based on INT”. Right there is a 3rd Edition rule, in the early ‘80s.

No Racial Attribute Penalties

Straight out of 4th Edition comes this house rule: removal of racial ability penalties. So if you’re an Elf, you don’t suffer –1 Con. The hard limits on attributes are still kept (although also changed), so you still can’t have an 18 Con Elf, but the fact is, back in the ‘80s, people were thinking: penalties are not fun. It took over 20 years for official D&D rules to catch up.


To Hit Armour Class 0 (THAC0) was introduced in 2nd Edition as a way of removing the rather complicated tables that you needed to work out Hit vs AC in 1st Edition. But enterprising gamers worked this out long before 2nd Edition was ever published…

It wasn’t originally called THAC0, of course: whilst THAC0 is a neat acronym, the version my dad had mirrored Armour Class: it was called “Combat Class”, or CC. Naturally, it’s mathematically accurate in a way that THAC0 never was: the official version mirrored the (with hindsight) unfortunate jumps and breaks in progression found in the original 1st Edition tables. Fighters, for example, increase their combat ability by 1 point every level, instead of 2 sometimes and 0 others. Wait, where have I heard that kind of progression before? Oh, right: 3rd Ed D&D, when they realised that sensible mathematical progressions make people more sane.

We may as well face it though: THAC0, while easier than its predecessor, was kind of stupid too. The correct way of doing Attack vs AC in D&D is still the 3rd Ed system. If you take AC = 20 – AD&D AC, and Attack = 20 – AD&D THAC0, then you have the 3rd Ed system. A fix in the wrong way is still wrong.

Armour limiting Dex bonus to AC

A useful rule that made its way into D&D in 3rd Ed, the house rules start very forward thinking: armour is split into Light, Medium, and Bulky, which affects AC mod. Except then it goes very 1st Edition: there’s an overly complex table where you compare Str, Dex, and Armour to get your AC bonus from stats. While it’s more simulation-ish dealing with the effect of Str, it is still overly complicated.

Dungeons & Dragons Classics

Clerics Stabbing People

Apparently my dad was none too happy with the weapon restrictions on Clerics. They’re opened up to all weapons. While it was historically accurate to priests who donned armour in the Middle Ages, it is not necessarily sensible to apply that restriction to all clerics regardless of the gods they follow. Evil Clerics were still restricted, but if you multiclassed to Fighter you were allowed to stab people with pointy objects. Go figure. Anyway, this is yet another rule that was only truly expunged in 4th Edition, although 3rd Edition tried its best.

Critical Hits (and Threats!)

The fact that my dad had critical hit rules was not surprising: it was so common that in the 1st Edition books, Gygax (who famously didn’t like critical hit rules) even commented about their non-inclusion, and the existence of house rules.

What is interesting is the way they were implemented almost exactly mirrors 3rd Edition. A threat (20 normally, 19-20 for “impaling” weapons) then requires a second confirmation roll, which must be a normal hit to confirm the crit.

The same rule, decades apart. Weird, eh?

Equal Opportunities

It was a pretty standard house rule to remove rules about different ability score caps for male and female characters. What’s more interesting is my dad was so certain about this that there is white out in the book.

Height and Weight

Actually I’m kidding. The house rules for these are so complex that we couldn’t work out how to use them, and gave up.

And More!

There is so much more than this. The rulebooks are littered with pencilled annotations, and various notes apart from them add even more house rules.

What’s even more amazing is when I talked to him about The Temple of Elemental Evil, my dad managed to dig up not only his notes, but original computer files of house rules. He’s been working at the same place for the last 30+ years, and it’s had consistent mainframe computer system the whole time. The files he found are ancient RTF files from the mid ‘80s. It’s rather incredible.

Just think about it: nerds have been using computers to write D&D house rules since the dawn of the game itself.

About Duncan

Ellisthion is currently loving 5E D&D, whilst still running the original 1st Ed AD&D Temple of Elemental Evil. He's also spending way too much time playing Dota 2.
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  • RupertG

    For those of you interested in Gygax’s opinions of house rules, including his distaste of Critical Hits, there is an awesome post about it over on Anthony Pryor’s blog.

  • Steve

    Will you guys be releasing your dad’s house rules at all? Like maybe as a PDF or something? I’d be really interested to read through them.

    • Ellisthion

      I’m considering trying. Some stuff is separate from the books and easy to publish, but a lot is spread through the books in notes and corrections, which is trickier. Sooo… maybe. :-)

  • Felonious Ham

    Those XP progression charts and spell charts are pretty amazing. I guess they didn’t have the advantage of being able to use computer spreadsheet programs to display the tables like that.

    • Ellisthion

      And yet my dad still managed, lol. I really have no idea how Gygax derived the original XP tables, they really make no sense.

    • Scrivenerof Doom

      Like a lot of Gygaxian things, there was no rhyme nor reason. Look at saving throw categories. They overlap and the progressions are random. And the thief has the –LOWEST– chance of actually jumping out of the way of a breath weapon attack.

      Anyway, great posts and I love the new XP progressions. That’s how they should be. :)

  • Monsta Ward

    Awesome stuff. Wish I had your dad growing up :(

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  • tlhonmey

    My group shares Gygax’s distaste of critical hits on a single D20 since the probabilities tend to be totally unfair. For a while we experimented with different combinations of dice to get a proper bell curve, but finally we went with simple. If you get a roll in the critical threat range, roll again and add. If you roll a 1, subtract 20 and roll again. Critical hits and misses become based on how badly you beat the other guy’s AC instead of the number. So far it seems to make for much more believable combat, and allows critical successes on skill checks without making the idea of an “escape proof” jail laughable.

  • james

    Actually, on the To-Hit table for Fighters, there is a text box below the table that addresses the 2-point increase every 2 levels…it says the DM may, if he wishes, increase by 1 point every level. It’s worded kind of weird, but that’s what it says.

    • Ellisthion

      You’re correct, and I had noticed that. However, it’s only one of a pile of random side rules and notes surrounding the pile of tables in that section of the book, and just adds to the confusion. It’s a very strange “rule”.

  • Nicholas Warcholak

    Great article. I love what your Dad did with the XP and spell progression. I can read the spell progression graph clearly, but not the XP one at lower levels. Would you be willing to share the tables for XP?

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