Thoughts & Things

Old School D&D Dungeon Module Conversion Guide

I’m writing an article on converting one of my favorite D&D modules for use with D&D 5th Edition. So I have a method that I’m using, and thought I should write down my thoughts. Maybe you guys like this stuff. 🙂  So what follows are the details of a conversion guide that I’ve put together that I am using. It may change as I get further into the conversion, but hopefully not a lot:


I have a lot of Dungeon modules in my library. After almost 40 years, I have collected a wide range of products. They are full of a lot of great ideas that I can just “stick” into any campaign that we are playing at the moment. Some that can’t be found by a web search by my players. 😉

So I was a little excited last year when we were told by Mike Mearls about free conversion guides of older material to 5th edition. Since that still hasn’t happened, then we are left to our own devices. I’ve put a little summary together, and here is the overall method of how I am going to go about converting things for my 1e and older modules:

  1. Keep the flavor
  2. Skills, Saving Throws & Ability scores
  3. Use Monsters from the Monster Manual
  4. Direct Conversion of Monsters (only if necessary)
  5. Use Magic Items from the Dungeon Masters Guide
  6. Convert Traps
  7. Weird Stuff

If you don’t have anything older that 3.5, then I would suggest that you embrace some old school products.  To get started, here are some reprints that are still out in the wild, and they are these two books: Dungeons of Dread Compilation (S1-S4) and Against the Slave Lords Compilation (A0-A4). These are great for your collection, and I use them with my 5th edition game.

1. Keep the Flavor

There is a large part in the modules that don’t need to be converted, because they are part of the story and don’t have a bearing on the mechanics. So when we talk about conversion, it’s mainly some of the mechanics. Usually monsters because of combat. Now, if changing that monster wouldn’t make sense or making an encounter super easy, then always fall back on the flavor of the story. Random encounter tables and rumor tables should just be left as they read. Remember, try to keep the “flavor” of the story.

2. Skills, Saving Throws and Ability Scores

Okay, now the easy stuff: Checks for success vs. failure. You can convert each ability check or saving throw into a Difficulty Class. But I only keep this if it adds to the story, and there is an alternative in case the character fails. You may find that some modules will ask for skill checks by using percentages or some other stuff. As it is with these checks, you have to roll under. So keep that in mind when you are converting things. So to make it all simple just flip it, and convert those percentages into a Difficulty Class. Low percentages are super hard, and high percentages are super easy.  Here’s an example that you can use: 0-10% DC 25, 11-45% DC 20, 46-75% DC 15, 76-90% DC 10. If success is 91 or lower, then skip it unless it adds “flavor” to the encounter, then make it a DC5.

Sometimes the adventure will ask for an ability check. Instead of converting to a DC, the ability score of the character becomes the a reverse DC. That means to roll a straight d20 without bonuses, and then compare the roll to the character’s ability score. If they Roll under then success, over for failure. If you want to keep that old school feel in the game, go ahead. This shouldn’t break anything.

3. Use Monsters from the Monster Manual

You can take each monster and replace it. Definitely do this with a monsters that will attack the party on sight. Find that is found in the Monster manual. If I don’t find one then I’ll replace all monsters from the old module with monsters from the DM basic rules. If there are several monsters, then be sure to use the DMG’s XP budget for number of monsters in a combat encounter.

This method should be fast and quick, and will save you a lot of effort. I’ll some examples below.

So as for a module like say, Keep on the Borderlands, here is how I would convert the Possible Combat situation for the Entry Yard of the Keep. This has a magic item that I didn’t change.

3. Entry Yard

They’ll meet the Corporal of the Watch along with two guards, scribe and some lackeys. I used a Knight (MM 347) as the base for this NPC. Change the greatsword to a Longsword +1 and add a shield & dagger. The Corporal of the Watch has the keys to the General Warehouse, he can lock up large goods in wagons or cart in #5 Common warehouse for storage while in town. I used Commoners (MM 345)for the Scribe and the lackeys. The Man at Arms are Guards (MM 347)

You arrive in the entry yard of

  • Corporal of the Watch – Mtn Dwarf Gindroth Rockminer AC 20. HP 11, Passive Perception 12, Initiative +1,  Longsword +1: +6 to hit, Hit 1d8+4 slashing damage.
  • Man at Arms 3 – Wood Elf –  Carric Nailo AC 18 , HP 11, Passive Perception 15, Initiative +1, Halberd +3 to hit, reach 10ft, Hit 1d10+1 slashing damage
  • Man at Arms 4 – Mtn Dwarf Darrak Ungart AC 18 , HP 13, Passive Perception 12, Initiative +1, Halberd +3 to hit, reach 10ft, Hit 1d10+1 slashing damage
  • Scribe – Rock Gnome – Breena Ningel (Breeze) AC 10 , HP 4 Passive Perception 10, Initiative +0, quarterstaff +2 to hit, Hit 1d6 bludgeoning damage.
  • Lackeys (unamed) will come from #4 Common stable to take horses. (use Commoners)

4. Direct Conversion of Monsters

If you don’t see it in the monster manual, or don’t recognize a monster, or just want to convert them on the fly, or just HAVE TO CONVERT THAT MONSTER!!!, then you can do it fairly easy. Note on AC: Some people will do a straight conversion on AC, but it’s not that simple with higher HD monsters.  You would think that an AD&D AC of 10 would convert to an D&D 5e AC of 10, with an AD&D AC of 0 converting to a D&D 5e AC of 20. but it’s more complicated than that.

Stan Shinn did a simple conversion document last year when the starter box came out, and just made some tweaks this past winter.  I like to use stuff that’s already out there. Here’s a link to his Combat tracker: http://goo.gl/ONB8OR

You can use Stan Shinn’s combat tracker, and follow these steps provided from Stan’s video below, and here is a link to his blog article where he goes through some conversions: http://swshinn.com/dnd-5e/5e-to-1e-combat-tracker. I even added a video where he explains everything.

1e — 1-1 HD, AC 6, 1d6 D
Converted 5e — 1d8+1 HD (5 avg), AC 13, 1d6+1 D
Actual 5e — 1d6 hp (3 avg), AC 13, +1/+2 To Hit, 1d6 – 1 D

1e — 4+4 HD, AC 6, +4 To Hit, 1d6 D
Converted 5e — 4+4 HD, AC 11, +4 To Hit, 1d6 + 4 D
Actual 5e — 4d10 + 8 hp (30 avg), AC 12. +4 To Hit, 1d6 + 3 DMG

Here’s Stan’s video:

5. Use Magic Items from the Dungeon Masters Guide

Magical items can normally be converted very easily like a long sword +1. You can just keep it in the adventure.

You may come across an item that you haven’t seen before, and many times you can keep the name and flavor and then just find an alternative in the DMG. If you don’t see it, change it to fit within the game, or just leave it out entirely. I’ve haven’t come across anything that can’t be easily converted & used in 5th edition yet. If you have, let me know.

6. Convert Traps

You can usually keep the traps the same, and change the effects to match the level the players. You can do this simply by having a DC to detect the trap, a DC to know how to disable the trap, and a DC to disarm the trap. All those DCs can be found on page 121 of the DMG. Then you only need to use the attack bonus, and the damage. Use the Damage Severity by Level table (DMG 121 or DMG 249) to determine damage to deal out.

Trap Save DCs & Attack Bonuses (DMG 121)
Trap DangerSave DCAttack Bonus
Setback10-11+3 to +5
Dangerous12-15+6 to +8
Deadly16-20+9 to +12

Damage Severity & Level (DMG 297)
Character levelSetbackDangerousDeadly
5th- 10th2d104d1010d10

Or you can take the sample traps from the Dungeon Master’s Guide and modify them if necessary. There are several example dungeon traps in the dungeon master’s guide (DMG 122-123), and a list of many other traps and a random table.(DMG 297). The sample traps are Collapsing Roof, Falling Net, Fire-Breathing Statue, Pits, Poison Darts, Poison Needle, Rolling Sphere and Sphere of Annihilation.

Here’s a trap that can be found on page 9 of Keep of the borderlands:

The strong room of the place is in the cellar. It is protected by a locked iron door which leads to a small vault with 12 compartments each protected by locks with hidden poison needles (save versus Poison at +1 or die).

This trap looks like it should be in the deadly category, and there is a sample trap called Poison Needle on page 123 of the DMG. So with a Trap Danger of Dangerous for 1st level characters, that gives it a DC save 15 and damage of 2d10. But this was a save versus poison, so I would set the damage and poisoned condition on a failed Constitution Save like the preceding Poison Dart trap in the DMG. Half damage on a successful save and no poison condition.

7. Weird Stuff

You may come across something that is strange and doesn’t really fit neatly into your gaming experience. Like a technology item flow chart from Expedition to the Barrier Peaks S3. If you look through the 5e DMG, you will probably find something that will get you close. So as an example, technology items are actually found in the DMG, look at DMG 268.

So if all else fails and you are frustrated, just ask someone. Tribality has a community board, and there is a Facebook Group that I created that you can go to for help: [https://www.facebook.com/groups/DnD5th/]. Just pop in and ask questions. You’ll might get a 1000 different opinions, and you get to choose which one you like for your game. 😉 or just send me an email: michael@tribality.com

So there you go, please remember that I consider this a living document, so as you and I use it, there will be tweaks and changes. But hopefully I’ve laid a solid frame work in order to utilize this effectively. Please let me know if you have any questions or suggestions. Thanks for Reading!



Dungeons of Dread Compilation: [http://amzn.to/1Fw7D9A]

Against the Slave Lords Compilation: [http://amzn.to/1VlUG3V]

Stan Shinn’s Blog [http://swshinn.com/dnd-5e/5e-to-1e-combat-tracker/]

Combat Tracker  [https://drive.google.com/file/d/0Byr-i7lu1I5INUxiaVRuSzk4dFU/edit]

D&D 5e Facebook Group [https://www.facebook.com/groups/DnD5th/]

Useful D&D 5e links: [http://tribality.com/dd-5th-edition-resources/]