Any tips on converting adventures?

I assume that BECMI adventures will be simply as is based on HD, but any suggestions on d20 stuff?

I actually wouldn’t mind guidelines for various version of DnD. Not necessarily anything rigorously mathematical, but more like ‘encounters are easier in AD&D modules, you might want to toughen some of them up’ or ‘2nd ed. was really skimpy on the treasure, add more baubles’. I always find it difficult to notice these things just reading through rules/modules.

Sure! Lots of thoughts in this regard.
B/X and BECMI Adventures:
These are the easiest to convert.

  1. Use ACKS attack throws and saving throws. Calculate ACKS Armor Class as (9- BECMI AC).
  2. Change any Halflings in the adventure to either Explorers, Thieves, or Dwarven Vaultguards, whichever seems more appropriate.
  3. Rebuild any dragons using the ACKS dragon tables. ACKS dragons can be more powerful than B/X dragons so you’ll have to decide what age range to make the dragon. Other monsters should be largely usable as is.
  4. Starting at 3rd level and up, ACKS characters are generally tougher than B/X adventurers, because of free casting, proficiencies and cleaving. You can usually run an ACKS party through an adventure 1-2 levels more difficult. Alternatively, increase the number of opponents slightly.
  5. B/X and BECMI modules usually have the right amount of treasure and magic items.
    1e AD&D Adventurers:
    These are relatively easy to convert.
  6. Use ACKS attack throws and saving throws.
  7. For NPCs of unavailable class/race combinations, you can substitute in an available ACKS class, or use the Player’s Companion classes and character customization rules (upcoming) to find a better fit.
  8. When calculating ACKS Armor Class from 1e sources, the direct conversion is (10 - 1e AC). However, 1e and ACKS assign a different relative value to actual armor. For example, in ACKS, Leather Armor is AC2 while Plate Armor is AC6 (a 4-point difference). In AD&D 1e, it’s AC8 and 3 respectively (a 5-point difference). I recommend you use the ACKS armor classes when you can directly calculate them.
  9. AD&D fighters have better attack throws and hit points than their ACKS counterparts. However, ACKS fighters tend have higher strength bonuses, deal higher damage, and get more cleave attacks, so it balances out. By and large ACKS PCs are equal in power to AD&D 1e PCs.
  10. Use ACKS monster statistics for any monsters that appear. Convert dragons to ACKS dragons of the appropriate age category. They will have comparable hit points yet more hit dice.
  11. When converting AD&D 1e modules, they will usually have the appropriate amount of treasure and magic items.
  12. Although 1e theoretically went up to 20th level and beyond, very few 1st edition characters exceeded 14th level. Those that do can be scaled down to 14th level in most cases.

2e AD&D Adventures:
Conversion of 2e AD&D to ACKS is by and large similar to conversion of 1e. There are a few differences, though:

  1. Giants and dragons are considerably more powerful in 2e. You will need to decide whether to use ACKS-equivalent or 2e-equivalent monsters.
  2. 2e tends to offer less treasure in its adventures, as the adventures are more based around story. You’ll need to review to make sure that the amount of treasure given is proportional to the number of monsters and other challenges (treasure in GP should equal 4 x monster XP).
  3. 2e uses proficiencies and kits for NPCs. These can be used as a guide to giving similar ACKS proficiencies, or simply ignored.

3e/3.5e D&D Adventures:
Conversion of 3e/3.5e material to ACKS is considerably more complex. You will have to choose between a formal or functional translation. In a formal translation you just want to work out the math. In a functional translation you want to capture the spirit.

  1. For a formal translation:
    ACKS Attack Throw = (10-3e Base Attack Bonus)
    ACKS Saving Throw = (20-3e Save Modifier; use Fort for Poison/Death and Paralyzation/Petrification; use Ref for Blast/Breath; use Will for Wands and Spells)
    ACKS Armor Class = (3e AC-10)
  2. For a functional translation: This is much harder, because 3.5 D&D is based on a true 1-20 leveling system, whereas ACKS is 1-14.
    A. When converting a monster that exists in ACKs, use the ACKS version.
    B. When converting PCs/NPCs/Custom monsters, set the creature’s HD or level equal to 1 per HD for the first 10 HD, and then 1 per 3HD thereafter, rounding up. For example, a 10th level Wizard becomes a 10th level Mage. A 15th level Fighter becomes a 12th level Fighter. A 20th level Wizard becomes a 14th level Mage. A 37HD Dragon becomes a 19HD dragon, while a 40HD Dragon becomes a 20HD dragon.
    C. Multiply the bonus of magic items by .66. A +5 magic sword becomes a +3 magic sword.
    D. 3.5 will not give enough treasure for ACKs. 3.5 assumes that low-level adventurers have considerably less treasure than in ACKs, but that’s in part because they assume more adventurers are higher level. Compare Table 5-1 (p135 D&D 3.5 DMG) to the Fighter XP Progression for an example. The problem gets worse every level until level 13, at which point the gap narrows.

On that note, I’m guessing that anything that’s Castles and Crusades (d20) will probably be the easiest to convert as 3e. That game has smaller damage values compared to other 3e versions.

Here’s my stab at 3e conversion. I took a dash of the SRD and added a pinch of the ACK vampire to get these suggested stats.
Aboleth example:
% In Lair: 80%
Dungeon Enc: Scourge (2d4) / Nest (4d6)
Wilderness Enc: Cavern (1) / Underground Lake (1d4)
Alignment: Chaos
Movement: 180’ (60’)
Armor Class: 6**
Hit Dice: 9 (Att. Throw +2)
Attacks: 4
Damage: 1d6+8
Save: F9
Morale: +2
Treasure Type: Q
XP: 1900
I believe in a “close enough” translation of monsters to save my time and sanity. :slight_smile:
“So close enough” would be:
Spell Casting: (Enslave, Psionics): Charm person, Confusion, Phantasmal Force, Feeblemind, Hold Person, Hallucinatory Terrain
Mummy Rot: (Damage by Slime)
Anyone killed by an Aboleth will arise as water breathing only minion in 3 days.
An aboleth has the Swim Proficiency.
The more literal Conversion might look like this (and add another “*” to the XP):
Enslave: Three times per day, an aboleth can attempt to enslave any one living creature within 30 feet. The target must succeed on a Spell Savings throw or be affected as though by a Charm person spell. An enslaved creature obeys the aboleth’s telepathic commands until freed by remove curse, and can attempt a new Spell save every 24 hours to break free. The control is also broken if the aboleth dies or travels more than 1 mile from its slave. Remove Curse also breaks this effect.
Psionics: Confusion, Phantasmal Force, Feeblemind, Hold Person, Hallucinatory Terrain
Slime: A blow from an aboleth’s tentacle can cause a terrible affliction. A creature hit by a tentacle must succeed on a Poison/Death save or begin to transform over the next 1d4+1 minutes, the skin gradually becoming a clear, slimy membrane. An afflicted creature must remain moistened with cool, fresh water or take 1d6 points of damage every 10 minutes. Remove disease reverses the affliction.
Mucus Cloud: An aboleth underwater surrounds itself with a viscous cloud of mucus roughly 1 foot thick. Any creature coming into contact with and inhaling this substance must succeed on a Poison/Death save or lose the ability to breathe air for the next 3 hours. An affected creature “drowns” on dry land in 10 rounds if removed from the water. Renewed contact with the mucus cloud and failing another Poison/Death save continues the effect for another 3 hours.
An aboleth has the Swim Proficiency.

Anglefish, that’s a great conversion. I may steal that to unleash it on my unsuspecting players.

I’m flattered. :slight_smile: Yes, you can sir. Please let me know how it goes. There’s a few typos. Even in a dungeon, you should only meet 1d4 at most. And the treasure might be closer to M than Q. And of course the ** go on the HD, not the AC.
Just out of curiosity, do you plan to use the “close enough” or the more literal translation?
Thanks again for the tips on conversion. I’ve gotten spoiled on certain SRD monsters over the years. And for me, the Aboleth have become my “Poor Man’s Mind Flayer.” If anything, the Aboleth is a more frightening mastermind behind an Invasion of the Body Snatcher/Dominated NPC conspiracy plot line.

Here’s my final stab at a conversion, with fewer typos hopefully.
Lich example:
% In Lair: 80%
Dungeon Enc: Cabal (2) /Troupe (2 + 4 vampires)
Wilderness Enc: Loner (1)
Alignment: Chaos
Movement: 9’ (30’)
Armor Class: 10
Hit Dice: 13*** (Att. Throw +0)
Attacks: 1+Spells
Damage: 1d10+ Paralyzing Touch
Save: F10
Morale: +3
Treasure Type: P
XP: 4400
Spell Casting: The lich casts spells like a 13th Level Wizard.
Paralyzing Touch: Any successful attack requires the opponent to attempt a saving throw versus Paralysis, or become paralyzed for 2d4 turns. This paralysis may be cured with cure light wounds.
Cause Fear: A modified version of the reversed spell of Remove Fear, causes ALL target creature within 120’ to become frightened; if the target fails to save versus Death, it flees for 2 turns. Creatures with 6 or more Hit Dice/Levels are immune to this effect.
Like all undead, Liches are immune to sleep, charm, and hold spells and poison.
Pylactery: This is a hand-held item (brooch, amulet, sword) that safeguards the Lich’s spirit. Unless the item is destroyed, the lich reappears fully healed in 24 hours.

Angelfish, I’d probably use the more detailed description. It’s very flavorful.
Should we create a forum where users can upload new ACKS monsters they’ve converted over?

Why not?

A conversion forum would be neat indeed.

Converting OD&D (I presume!) movement: does X“ => 10X’ (3.33X’) seem right?

Movement conversions between editions is both more complex and more simple than it ought to be. you mibht want to look at a blog post I wrote onthe subject a few daws ago
It comes down to basically not changing the rates as given because CHAINMAIL movement rates were used conistently in all editions up to 3e, without converting to the changed time interval.