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

kotb1 Old and new together is better than keeping them apart

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.

kotb2 Old and new together is better than keeping them apart

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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