Converting 1st/2nd Edition Modules to 4th Edition

Hey everyone,

I'm hoping to convert some classic 1st and 2nd Edition D&D modules to 4th Edition. Converting monsters and creating balanced encounters is no trouble at all--the problem is the sheer number of encounters!

Allow me to explain. In the standard rate of advancement, PCs gain a level every 8-10 encounters. That works great in currently-published 4E adventures (all the ones I have seen take the 8-10 encounters into account when designing dungeons from scratch). Of course, in 1st and 2nd Edition, leveling went at a much different pace and encounters were balanced differently.

I would love to run a long 'dungeon crawl', such as the Temple of Elemental Evil or The Tomb of Horrors. The problem is that most previous-edition modules assume there to be an absurd number of encounters.

Consider, for example, Dungeon Level 1 of the Temple of Elemental Evil: there are roughly 53 areas and about 30 encounters in them. In 4th Edition, 30 balanced encounters of appropriate challenge mix (see page 104 of the DM Guide) would equal 3 character levels. Considering that the Temple of Elemental Evil supermodule has two Moathouse levels, about three exterior Temple areas, four Temple dungeon levels, and four nodes of elemental evil, not to mention bazillions of random monster encounters--I estimate that if I were to segment the areas into 8-10 encounter blocks, I would come out with a whopping total of 15-ish character levels. Gah!

But what is the problem with that, you might ask. Well, the recompiled T1-4 supermodule was intended to move onwards into the A series and the wonderful GDQ series, all of which include massive dungeons too. If this rate of advancement were kept up from T1-4, the PCs would reach maxed-out 30th-level quite a ways before they even came close to meeting the drow.


Have you tried to convert an early module into 4E, and if so, how did you manage to deal with the rate of advancement issue? I have come up with only a few ways to deal with this, myself:

1. Slow the rate of advancement as suggested in the DM Guide--perhaps cutting the XP gain in half. That would mean the PCs might gain roughly 8-10 levels in the course of completing T1-4 (possibly a few more). That would be nice...but might also be fairly unexact and would probably still conflict with the addition of the A series and GDQ series.


2. Just run with it, giving the PCs standard experience for the encounters. Unfortunately, this choice has many negatives--as noted above, the PCs' level by the end of T1-4 would be considerably high and there may not be enough levels 'left over' to run the A series and GDQ series. Another major issue with this choice is balancing the encounters in the dungeon itself. If there are 30 encounters roughly every dungeon level, that means that every 10 of those need to have appropriate, balanced mix.

But the rooms in the dungeon are strewn everywhere on a convoluted map, which means the PCs could very easily stumble into an encounter far above their own level. Deciding which encounters are more challenging than others for the encounter mix's sake would be difficult as well.


3. Completely alter the PCs' rate of advancement for this adventure. That would entail ignoring XP altogether and simply grant a level at an appropriate point; such as, say, at the end of each completed dungeon level. This choice has the benefit of preventing major balance issues and it permits me to balance the encounters quite simply, as I can then assume that all PCs when on a given dungeon level are of a particular character level and thus adjust the encounter level mix accordingly (whew!).

The main downside of this choice is that it is extremely weird and is not even mentioned as a possibility in the DM Guide (unless one considers the 'simpler experience points' on page 121 as alluding to it in a way), thus making some other DMs to whom I may present my conversion notes shake their heads and say, 'I can't just tell my players they only gain levels at a certain spot!' This choice is definitely not preferable to me for that reason--as I'm a by-the-book DM in many ways. But I wonder if this is the only feasible way to convert these classic dungeon crawls.

What do you think? How would you convert these old dungeons into workable 4E ones, in terms of encounter balance and XP rewards (and possibly treasure awards too, tied into that calculation)?

Thank you in advance for any help or advice you may offer!

You have to break out of the mold of "one room, one encounter".

4E encounters can often involve several rooms and are supposed to be mobile and dynamic.

When looking at a 30 room dungeon from 1st edition, instead of looking at each room as a single encounter, you need to group rooms together into single encounters and balance them appropriately, keeping the theme together.

Figure out how many levels the PCs should gain while exploring the dungeon, and multiply that by 10, and then divide the dungeon into that many logical regions. Look at the original module and take the theme presented in each group of rooms and create a single encounter that fits the theme.

A perfect example is the Chamber of Eyes in H2. It's a "dungeon" with 10 rooms, but only 4 encounters. Yes, there are monsters in many of the rooms, in fact, the fourth encounter spans 5 rooms, with three different "groups" of monsters, but it's a single balanced encounter.

Bumamgar said:

You have to break out of the mold of "one room, one encounter".

4E encounters can often involve several rooms and are supposed to be mobile and dynamic.

When looking at a 30 room dungeon from 1st edition, instead of looking at each room as a single encounter, you need to group rooms together into single encounters and balance them appropriately, keeping the theme together.

Figure out how many levels the PCs should gain while exploring the dungeon, and multiply that by 10, and then divide the dungeon into that many logical regions. Look at the original module and take the theme presented in each group of rooms and create a single encounter that fits the theme.

A perfect example is the Chamber of Eyes in H2. It's a "dungeon" with 10 rooms, but only 4 encounters. Yes, there are monsters in many of the rooms, in fact, the fourth encounter spans 5 rooms, with three different "groups" of monsters, but it's a single balanced encounter.

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That is a fantastic idea, thank you!

I do foresee some issues with it, though, in T1-4. The Temple's inhabitants tend to despise each other and although they are noted to work together at particular points, other times they seem to ignore each other's troubles entirely.

For example, in areas 103-107 on Dungeon Level One of the Temple of Elemental Evil, there are some harpies and several groups of ghouls. Specifically, there are two harpies in 103, six ghouls in 104, another six ghouls in 105, and two ghasts in 107 (106 is empty).

As written, the ghouls in 104 come to help out the harpies if the harpies are attacked--but the ghouls in 105 are supposed to completely ignore the conflict, believing that their comrades will be fine. The ghasts are totally oblivious.

Now, of course, I could ignore the module as written and group all of the ghouls and harpies together in one large encounter, but that would kind of defeat my goal, I feel, of converting the module as faithfully as possible. I hope that makes sense.

That said, though, I checked Thunderspire Labyrinth's C4 encounter on page 9 of book 2, the one to which you were referring. The 'tactics' text does say that if the PCs attack location 10 first, all of the groups wind up getting involved in one large combat. However, if the PCs enter location 6 first, only one of the other groups runs in to help whilst the third stays put. I do have a question, though (and this may be a stupid one, but I'm trying to wrap my brain around this encounter style, so do forgive my idiocy). If the PCs were to enter location 6 first and defeat those two groups (and the third did not join in), would the encounter count as 'finished'? Would the PCs be able to take a short rest to recharge encounter powers, or do they first need to head into location 10 (the site of the uncaring third group) and kill off group three? Is an encounter still a full, challenging encounter if the PCs really only battle some of the monsters within it?

To clarify what I am asking: in the Moathouse of T1-4, there is a room with a giant tick, a second room with a giant snake, and a third room with a giant lizard which are relatively close to each other. Neither the giant tick, the giant snake, nor the giant lizard alone make a suitable challenge unless they are turned into solo monsters (turning a small-size 'giant tick' into a 1st-level solo skirmisher is a bit bizarre, but I could rationalise making the snake and lizard into solo monsters). The monsters are totally unconnected--the giant lizard doesn't care at all about the giant snake, of course, and they certainly would not team up against the PCs in one big battle. In such a situation--of which there are many in T1-4--does it still make sense to connect the monsters into one 'encounter', even though they are fought one at a time? Doesn't facing the monsters one-by-one lessen the encounter's overall difficulty?

A 1st-level encounter for 5 PCs gives 500 XP. Let's assume that the giant snake and giant lizard are both 1st-level elites (therefore counting as four 1st-level monsters) and the giant tick is 1st-level. If these monsters were fought in one big combat, then they would constitute an encounter worth 500 XP, which would count as one of the three 'Level + 0' encounters of the 1st PC level (as per 'Encounter Difficulty' mix on page 104 of the DM Guide).

But these monsters are unconnected and will not rush to help each other. Let's say that the PCs head over to kill the giant snake (200 XP). They do not even go into the rooms containing the lizard and tick; instead, they head out of the moathouse and back to town for some random reason. They return later, after having a rest, and kill the lizard and the tick (300 XP). Now they have their 500 XP total for the 'encounter', but wasn't the encounter really two encounters, both of which were considerably easier than the suggested single, equal-level encounter?

If C4's alternative tactics (if the PCs enter through location 6 and only face two groups instead of all three of the ones which constitute the full encounter) really play out the way I assume they do, then the above ghoul/harpy/ghast encounter from the Temple of Elemental Evil would work brilliantly rolled up as one encounter instead of several, because it could still be run as originally written yet remain a suitably challenging 4E encounter. But if 'unconnected' monsters cannot be strung into one encounter on account of their being fought one at a time like the giant snake et. al., then there will still be some issues, I imagine.

Mearls has a couple of articles up at the Wizards site that talk about converting old adventures. They mainly focus on converting the encounter aspect and not the levelling aspect, though. The big problem with trying to faithfully convert the T-A-G-D-Q series over to 4e would be that the monster levels won't easily map into the adventure levels. Drow are levels 11-15, Kuo-toa levels 12-16, hill giants level 13, fire giants level 18, Lolth would be epic-level probably...

Spatula said:

Mearls has a couple of articles up at the Wizards site that talk about converting old adventures. They mainly focus on converting the encounter aspect and not the levelling aspect, though. The big problem with trying to faithfully convert the T-A-G-D-Q series over to 4e would be that the monster levels won't easily map into the adventure levels. Drow are levels 11-15, Kuo-toa levels 12-16, hill giants level 13, fire giants level 18, Lolth would be epic-level probably...

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Yes, that's true. Many (if not most) of the monsters need to have their levels adjusted, and many need to be recreated outright as new monsters. I do not mind that, though; in fact, recreating 1E monsters in 4E format is great fun! What is throwing me off is the leveling/encounter issue; I cannot design monsters without knowing what levels they should be in order to fit into their associated encounters. So, my work on T1-4 is pretty much stalled until I can figure out a good solution. Bumamgar had an excellent suggestion above, but I am not sure how well it would work in T1-4 if the PCs can just wander off, not bothering to check the nearby rooms for monsters in the same 'encounter' who do not normally come to their allies' aid.

Romanstoic, I recently ran the T1 Moathouse at Origins, in 4th Edition, for 1st level characters. It wasn't really too difficult to convert.

The thing to keep in mind is that 4th Edition isn't nearly as bad about differing monster levels vs PC levels. That is, you can throw a level 4 or 5 monster at a level 1 party without a guaranteed wipe. Use slightly higher monsters for your single creatures.

The giant frogs: two lvl 3 lurkers = 300 xp (an easy fight)
HP: 38
AC: 16, Fort 15, Ref 15, Will 12
Init +7
Attacks:
* Tongue: +7 vs Ref and opponent is grabbed. Opponent is immediately transferred to mouth for bite attack.
* Bite: +9 vs AC, 2d6+3, plus the target is grabbed (until escape). The giant frog cannot make bite attacks while grabbing a creature, except versus that creature.
* Swallow whole: Giant frog attempts to swallow a bloodied Medium or smaller creature it is grabbing; +6 vs. Fortitude; on a hit, the target is swallowed and restrained (no save) and takes ongoing 5 acid damage on subsequent rounds at the start of its turn (no save). The swallowed creature can make melee basic attacks only, and only with one-handed or natural weapons. If the frog dies, any creature trapped in the gullet can escape as a move action, ending that action in a square formerly occupied by the frog.
Skills: Stealth +10

Those were pretty tough for my group at first due to surprise, but eventally went down without too much damage to the party. Easy, fun.



The spider was a Deathjump spider from the MM (level 4 lurker). I actually downgraded it to a level 2 lurker because I saw that encounter to be a minor distraction & spook than anything else.



The bandits consisted of:
* 4 human bandits (downgraded to level 1) = 400 xp
* 4 human bandits (ranged variant - gave them agile shot instead of dazing strike) - minions, so worth xp of 1 more front line bandit = 100 xp
* A level 3 human Guard. Gave him a bastard sword & shield instead of a halbard. His AC was 19 (1 higher), and I changed his powerful strike to a 2[W] attack, recharge 5, 6, without knockdown. = 150 xp. In retrospect, I might have made him an Elite to bring the xp to 300.

Total xpv for bandit fight (first real fight in the module) = 650. That's 1 level higher than the party - not too tough. If I had made the captain an Elite, it would have been 800 xp, less than a level 4 encounter. I would expect 1-3 daily's to be used, but the rest of the moathouse top wasn't too hard, and I suspected that the party could finish clearing the top with only encounter powers.



The snake was easy: a single deathrattle viper (level 5) from the monster manual. At only 200 xp, pretty easy. Normally, +4 levels on the party means really high to hit bonuses or high AC, but the viper from the MM isn't too tough. 17 AC, +8 to hit, he's not insane.



The tick was always a bit strange, so I changed it to eight stirge minions (level 1 lurkers), worth 200 xp.



The lizard became a level 3 elite brute: (
HP: 112
AC: 17
Fort: 18, Ref 16, Wil 14
Attacks:
* Bite: +6 for 2d6+3
* Powerful Charge: charge attack also knocks opponent down
Abilities
* Combat advantage: +1d6 vs. creatures it has combat advantage against
* Chameleon: +5 to hide checks if immobile
* Bloodied Bite: Immediate bite attack when bloodied.



That about sums up the 1st level. Oh, if you need some maps of the Moathouse, temple grounds, Inn of the Welcome Wench, Waterside Hostel, and Dungeon Level 1, check out my maps pages. They are at 100 pixels per 5 ft scale. Just click on the buttons for sub-pages.

DM: "Hey guys, I want to run ToEE, but the XP charts are all messed up. Rather than count XP, I'll just let you know when you level up. Cool?"

PCs: "Cool. ToEE rocks."

Irda Ranger said:

DM: "Hey guys, I want to run ToEE, but the XP charts are all messed up. Rather than count XP, I'll just let you know when you level up. Cool?"

PCs: "Cool. ToEE rocks."

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That's pretty much what I did when I ran it converted to 3.5, and my players loved it.

Getting rid of XP is one of the most simple yet profound things you can do as a DM. It keeps your players focused on story and their own objectives, not monster hunting or metagame. I found that my players actively sought out more non-combative solutions to problems, were more likely to let bad guys live, and generally were less blood thirsty. Give it a try!

I may one day run it in 4th Edition - but I'm just starting Paizo's Rise of the Runelords, converting it to 4th - brilliant writing, Paizo!

Irda Ranger said:

DM: "Hey guys, I want to run ToEE, but the XP charts are all messed up. Rather than count XP, I'll just let you know when you level up. Cool?"

PCs: "Cool. ToEE rocks."

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You do realize that that is not the point of the OP right? Building balanced encounters that are either not going to be too easy or too hard is the actual difficulty here.

And it is a legitimate concern. I'm converting B5 Horror on the Hill right now and realize that, as written, this is a meat grinder of the 1st order. I having a heck of a time figuring out how to balance things so that the monsters behave logically but Bumamgar's idea of grouping them by room is solid. I will have to take a fresh look at it and see what I can come up with.

Holy Bovine said:

You do realize that that is not the point of the OP right? Building balanced encounters that are either not going to be too easy or too hard is the actual difficulty here.

And it is a legitimate concern. I'm converting B5 Horror on the Hill right now and realize that, as written, this is a meat grinder of the 1st order. I having a heck of a time figuring out how to balance things so that the monsters behave logically but Bumamgar's idea of grouping them by room is solid. I will have to take a fresh look at it and see what I can come up with.

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Actually, that is the point of the original post, is the experience and number of encounters. Building balanced encounters was a footnote. BTW, B5 is awesome. One of my favorites.

Figure out what level you want the characters to be after wiping out certain areas. Do away with XP altogether. It is very liberating.