Old and new together is better than keeping them apart

I have a deep love of classic D&D modules. I also love Fourth Edition, and find that adapting classic modules to 4e is almost ridiculously easy to do. In may ways the end result is even better than the original with dynamics, tactics and options jumping off the page. That’s partly a result of the sheer quality of the many modules we now call classics, but also down to 4e’s design. Put the two together, and you’re looking at pure gold.

Don’t believe me? Here’s an example.

Let’s use the veritable and most loved adventure module of all – B2 Keep on the Borderlands. In the Caves of Chaos, Encounter Area A is a Kobold Lair which is made up of the following:

Entrance: 8 Kobolds and a 10′ pit trap
1. Guard Room: 6 Kobolds
2. Garbage Room: 17 rats + 1 large rat
4. Guard Room: 3 large Kobolds
5. Kobolds Chieftain’s Room: Chief & 5 Kobolds
6. Common Chamber: 40 Kobolds & 8 non-combatants


Now, with an open copy of the 4e Monster Manual by your side I’ll lay odds any half-competent GM could run that as-is right off the page, just replacing the Kobolds with appropriate stats as required.

But a wise GM will do more. In 4e, an Encounter isn’t necessarily tied to a single room or location but can spread over several different rooms with all of the opponents moving and interacting at the same time. This is a simple premise of encounter design which Wizards of the Coast advocated then promptly forgot in it’s own published adventures. Silly adventure writers!

With that in mind, let’s add a few Encounter Zones to the map and populate them accordingly.


Encounter 1: Outside and Entrance
Eight Kobold Minions, One 10′ Pit Trap and Three Kobold Slingers, 600XP

The Eight Kobold Minions are hiding in and among the trees outside the lair (Perception DC14 to spot). They break cover and try to push opponents into the pit trap while the Slingers in the Guard Room fire through the doorway. If anyone falls into the pit one of the Slingers holds an action to fire at him if he climbs out – DC15 Athletics check to prevent falling back in if hit.

Encounter 2: Rats!
Two Rat Swarms, Six Giant Rats, One Dire Rat, 500XP

Room 2 is big and crowded enough to count as a single Encounter Zone. Rat attack!

Encounter 3: Corridors, Guard Post and Chief
Three Kobold Dragonshields with Shortbows (+6, 1d6+2), One Kobold Wyrmpriest, Five Kobold Minions, 650XP

The corridor leading to Rooms 4 and 5 is nothing less than a deathtrap for foolish PCs. It’s 70′ long (14 squares in 4e terms) meaning it’ll take two rounds to reach Room 4 which contains 3 Dragonshields who snipe at anyone non-scaly who approaches. It’s going to take serious blasty magic to take them out, and any noise will attract the attention of the Wyrmpriest Kobold Chief and his harem of Minions.

Good luck with that.

Encounter 4: Common Room
It’s tempting just to drop 40 Kobold Minions in here and just sit back, but instead let’s get creative. And by “get creative”, I mean use the internet to find a fun alternative.

Add the Swarm Template to the Kobold Skirmisher and we’ve got a Kobold Swarm. Drop two in the room and a handful of minions to represent stragglers, and we’re done.

Two Kobold Swarms, Four Kobold Minions, 500XP

There you have it. One part of the Caves of Chaos, 4e-ified. Awesome, no?

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13 Responses

  1. CharlieAmra says:

    Lazy DM my broadsword. . .this is pure genius. Thanks for posting these creative and simple conversion ideas.
    .-= CharlieAmra´s last blog ..As My Dreams Died-redux =-.

  2. dr. checkmate says:

    I love two things about your 4e posts. You are honest in your affection for the game while at the same time maintaining a critical eye towards WotC’s business model. Thank you.

    That said, I wish someone around here would run this damn game so I could give it a fair shake, but to the best of my knowledge, no one is.

  3. I think this is a testament to the quality of the original adventures.

  4. dr. checkmate says:

    I think adaptability would be the hallmark of any good adventure.

  5. I. Want. To. Do. This. Now.
    .-= The Last Rogue´s last blog ..A Minor Update =-.

  6. by_the_sword says:

    Keep on the borderlands is probably the most useful and adaptable adventure ever written. it’s practically a mini campaign and if every encounter in it were converted to 4th edition, then you could get your players through most of the heroic tier…

    …if they don’t die that is.

    One thing I might change is the width of the entry corridor to 5′ wide. This will allow 2 kobolds to stand side by side but only 1 medium sized creature. I would also move the location of the pit to just outside the entryway with enough room for a small creature to casually stroll around, yet still in a position to trap a charging adventurer.

  7. dar says:


  8. Best RPG blog post I’ve read this week. Superb!

  9. Awwww, man, that takes me back… that was my first adventure module. Actually, for a long time, it was my only adventure module, so I built a whole campaign around it. Kobold factions (some of them were agitating for political recognition from the humans) and everything.

    The set it came with sure didn’t have rules for anything but combat or basic exploration, but that didn’t stop us from throwing in politics, trade, intrigue, or anything else that we were interested in. Kids today and their music, and so forth.
    .-= Alexandra Erin´s last blog ..Strange criticism of the moment… =-.

  10. kaeosdad says:

    Nice job! I like the way you set up the encounter zones highlighted in red. Gives me a few ideas…

    this reminds me, this one guy converted keep on the borderlands awhile back and it can be d/l here: http://www.dndcorner.com/downloadable-files/

    But his conversion is a more straightforward updating of stats. I like this 4e style redesign. Awesome post!
    .-= kaeosdad´s last blog ..Mysterious Alien Dice Revealed!!! =-.

  11. Greywulf says:

    @kaeosdad Oh that’s excellent! Thanks for the link. He’s set it beginning around Level 3 where I’d prefer starting right at 1st level, but apart from that it’s perfect :D

  1. February 7, 2010

    […] case of grabbing the map and blocking out Encounter Zones. This uses the same technique I used for 4e’ifying the first part of B2 Keep on the Borderlands. Find existing encounters that would work well if grouped together and you’ll find dynamics […]

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