Converting from 2E to 5E D&D

• 08 November 2024
• reference,
• procedure
• ~ 5 min read

Converting from 2E to 5E #

I've been revisting some older D&D content this year, being the 50th anniversary of "the world's greatest roleplaying game". In particular, I've been enjoying the layout, lore, and table-formatting of Dead Gods, an epic Tier 2 romp through the planes in an effort to thwart an undead god bent on vengeance.
That got me thinking about how I might run this content at a 5E table...

I really like how tightly formatted the NPC/Monster stat blocks are in 2E, and especially Planescape.

For example:

GITHYANKI WARROR, Pl/♂ githyanki/F4/CE: AC 3 (banded mail); MV 12; hp 24;
THAC0 17; #AT 1; Dmg 1d8 (longsword); SA plane shift at will; SZ M (6');
ML steady (12); Int 15; XP 270

That's pretty information-dense. Let's unpack that:

The Planescape NPC Abbreviations #

Pl/♂ githyanki/F4/CE is a Planescape-ism for humanoids and NPCs, a sort of Geek Code shorthand indicating the most important, salient facts about the being in question. The left-most section is for planar origin, and is typically one of:

• Pl for those born in the outer planes.
• Pr for those born in a prime material plane.
• Px for those acting as proxies for a power.

These are all Planescape-setting specific details.

The next section is self-explanatory: gender icon and race/species.

This is followed by a Class+Level abbreviation, where class is typically:

• F ighter
• W izard
• C leric, or
• T hief

So F4 is 4th level Fighter. F2,T5 might indicate a multi-classed character with 2 levels of fighter, and 5 of rogue.

Optionally present but missing in the above githyanki example would be a Faction or faction abbreviation. For example, Duskmen. This is setting-specific, also.

Finally, we have alignment, e.g. CE indicates Chaotic Evil.

What's cool about these NPC abbreviations is that they are often featured inline in an adventure text. For example:

Walking through the market, the PCs might encounter Zarathustra (Pr/♂ hu/C10/Godsmen/LN), who greets them with mock indifference.

Rather than distract with a whole statblock or simply dropping a bolded reference to a common NPC statblock one could reference if they had the motivation, it functions almost like a textual Sparkline. I really like this idea.

The 2E Statblock #

Unrolling:

AC 3 (banded mail); MV 12; hp 24; THAC0 17; #AT 1; Dmg 1d8 (longsword); SA plane shift at will; SZ M (6'); ML steady (12); Int 15; XP 270

AC 3: Armor class. 2E armor class is essentially inverted from 5E, so to convert this, subtract from 20: 20 - 3 = 17, a reasonably well-armored fighter in 5th edition mechanics.

MV 12: Movement Speed in tens of yards. In 2E this would indicate 120 yards per 1-minute round. 5E tries to abstract rounds to 6 seconds. This is all a little wibbly-wobbly, honestly. There's not, to my knowledge, a really simple and clean way to map these onto 5E movement speeds, but I have found that a rough-and-ready conversion that seems to work is: 5E movement speed = 2.5 * 2E MV. In 2E, MV 12 is pretty common for humanoids. That works out to a 5E Movement Speed of 30, which, whadyaknow, is pretty common in 5E. This multiplier breaks down a little at the extemes of very slow or very fast, but it's easy to remember.

hp 24: Good ol' Hit Points. It seems there's been some hp and damage scale creep over the editions, so a scaling factor of 1.5 seems about right, putting HP into the 75% or so of range by CR (or in this case, character level). 24 hp in 2E becomes 36 hp in 5E.

THAC0 17: "To Hit AC Zero", a number that indicates what must be rolled or surpassed to hit a notional AC of 0. If you've not played the 1st or 2nd editions of the game, this likely looks weird. I mean, it is weird, we just didn't know any differently back in the day. Thankfully, this is easy to fix by replacing it with Attack Bonus. Just like AC, 5E Attack Bonus = 20 - THAC0. So, our Githyanki fighter has an attack bonus of 20 - 17 = +3.

#AT 1: Number of attacks. Straightforward.

SA plane shift: Special Abilities. Actions that have spell-like effects.

SZ M: Size Medium.

ML Steady (12): Morale. Not a mechanic used much in 5E, although there is an optional rule on page 273 of the DMG: make a DC10 Wisdom Saving throw when certain battlefield conditions are met. Since we almost never have all six attributes (Strength, Dexterity, etc.) listed out in a 2E statblock, we'll fudge this wisdom save bonus: 5E Morale Save Bonus = 2E ML - 10. Our Githyanki with an ML of 12 therefore has a +2 bonus on a DC10 Save.

Int 15: In 2E most of the physical stats, for combat purposes, are baked into the AC, THAC0, and hp numbers. There just wasn't mechanical need to list them out like we need to in 5E. Int mostly indicated what kind of tactics the DM should use (how "smart" to play the fight), as well as indicate what kind of spell resistance or mental/psionic defenses the creature has. There's no need to modify this number, as it is largely a historical artifact. In a pinch, you could probably use this attribute to cover all 'mental' stats (Intelligence, Wisdom and Charisma): 5E 'mental' stat bonus = INT bonus. So our Githyanki has a +2 bonus to all mental stats.

This kind of begs the question about the other missing stats, though. How to fudge the physical stats?

Honestly, the easiest thing here is probably 5E 'physical' stat bonus = HD / 2 (round up). So, an 8HD creature would have a +4 physical stat bonus (initiative, strength or dex checks, con saves, etc).

XP 270: Experience Points. These are really swingy. 2E level advancement numbers are about 8 times higher on average than 5E level numbers. That said, it really doesn't seem to make any sense to divide the 2E number by 8. Here, that would yield around 34 xp, which is somewhere between the xp awarded for CR 1/8 and CR 1/4 in 5E. This Githyanki Warrior is probably a CR 2 or 3 in 5E terms, which would yield 700xp. My gut feeling here for a rule of thumb is: 5E XP = XP of CR (HD -1). So, our Githyaki Warrior has 4 hit dice, we'd award 700xp (as though it was CR 3).

Here's a table of XP values by Challenge Rating (CR) in 5th Edition D&D:

All Together Now #

Putting this all together now, if we wanted to rewrite the above statblock in 5E terms, we'd get:

GITHYANKI WARROR, Pl/♂ githyanki/F4/CE: AC 17; MV 30; hp 36;
Atk +3; #AT 1; Dmg 1d8+4 (9); SA plane shift at will; SZ M;
ML +2; Mental +2; Physical +2; XP 700 (CR3)

Of course, the point of having rough-and-ready conversion guides is to avoid having to reprint old 2E material in order to use it at a 5E table.

Therefore, I've assembled this cheat sheet:

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