How to convert 3.5 module to AD&D

[StylinLP]

Is there a source on how to convert all sorts of things like Rules, Monsters, magic items from 3.5 to AD&D? Specifically, I picked up a wonderful resource D20 book called Demonology. Need to covert the spells, feats and skills to AD&D. What is a dc20 roll in AD&D? Thanks!

 

[thedungeondelver]

Is there a source on how to convert all sorts of things like Rules, Monsters, magic items from 3.5 to AD&D? Specifically, I picked up a wonderful resource D20 book called Demonology. Need to covert the spells, feats and skills to AD&D. What is a dc20 roll in AD&D? Thanks!

Forget the feats, skills and etcetera. Where skills with a specific DC are required, or saving throws, extract out the appropriate 1e saving throw. You can do the same for skills, or use "stat checks" (roll d20 under a given stat that makes the most sense). I tend to lean more on saving throws for AD&D where necessary, as they improve over time and are based generally on the stats that are required to figure things out (high Wisdom score improves some saves, high Dex others, and high Con others still).

As to monsters, crank the HP and HD way, way down, ditch the "template" system, look at whatever treasure they're given then cross-compare it to the Treasure Type table in the MONSTER MANUAL.

Spells, so long as they don't require metamagic feats and such, can probably stay as written, just come up with something in the way of spellcasting time that makes sense. Protip: level of spell = segments of casting time for magic-user spells (any spell listed as "Wiz" or "Sorc"), level of spell + 2 = segments of casting time for cleric spells.

As to the "what is a DC20 in AD&D" it is wholly dependent on context of when it is called for.

 

[RFisher]

You can do the same for skills, or use "stat checks" (roll d20 under a given stat that makes the most sense). I tend to lean more on saving throws for AD&D where necessary, as they improve over time and are based generally on the stats that are required to figure things out (high Wisdom score improves some saves, high Dex others, and high Con others still).

In the few conversions I’ve done, most skill checks just got eliminated.

Instead of a spot check, just include it in the description up front. For some spot checks, the players may need to actually say the look at something first.

Instead of search checks, if they search, they find it.

Instead of knowledge checks, just give them the background—providing it is interesting or useful.

et cetera

I didn’t even bother to finish writing out the conversions since they were almost universally...

• “substitute this monster stats from this edition instead” or
• “substitute the standard rule for this edition instead” or
• “just handle it as if the skill check succeeded”