Running Xyntillan: Magic Swords

Since wrapping up the Castle Xyntillan campaign I’ve been kind of busy with work, then summer happened. And now I have emerged out from under a deadline and so here then finally is another blog post. We have recently kicked off a new campaign, Planet Karus, which I will share more about soon, but first I have a few more posts on Castle Xyntillan planned, focusing on how I ran the game: methods I developed, problems I solved, that sort of thing. Hopefully it is of some use. To start things off relatively manageable, I will talk about the magic swords. This was inspired by a recent comment left by Michael.

The issue

Here’s the issue: Castle Xyntillan has several intelligent magic swords littered throughout. The treasury (page 122-123) lists seven in total. In all cases, an EGO score is included, but, somewhat curiously, no intelligence (INT, excepting the wonderfully curious Rabbit Sword). Furthermore, Swords & Wizardry, the OD&D retroclone for which Castle Xyntillan is nominally written, has no rules for how to deal with intelligent swords. In my case, I cared about two things: how do I determine if a sword is able to communicate with its wielder (and in which fashion), and how should I read the EGO score for purposes of what OD&D calls “egoism” and B/X (the expert set specifically, on page X47) “control”.


Back in November 2020, after a session in which I had to improvise sword control on the spot with unsatisfactory results, I asked Melan about this via email, and he shared that in fact, they were using Hungarian retroclone Kazamaták és Kompániák to playtest the module. Gaps in the rules they would fill out using OD&D.

With this knowledge, I looked at the EGO scores in the module, and noticed they regularly exceed 12, which is the upper limit in OD&D. You are supposed to add up EGO, INT, and a point for each extraordinary ability for a total score ranging from 8-28 (what B/X calls a “willpower” score).

Anyway, the crucial bit in OD&D is this: Intelligence, which is a score ranging from 1-12 not only determines communicative ability, but also the number of powers a sword has. So by analyzing the powers listed for each sword in Castle Xyntillan, we can reverse-engineer its INT. The resulting scores are listed in the table below.

NameListed EGOINTCommunicationAdjusted EGONotes
The Blade of Rel177Empathy10
Darkslayer1510Speech5Book states it speaks
Onwards!2412/7Telepathy/Empathy12/17See extended note below
Rabbit Sword118Empathy3Book lists INT of 8
Intelligence of magic swords in Castle Xyntillan

Special note on Onwards!: Looking at its power in question, it is a lawful blade that can paralyze chaotics. This suggests it is in fact a sword with a special purpose (see page 30 of OD&D volume 2). OD&D says such swords have the maximum intelligence and ego scores. However, Castle Xyntillan states the sword is “fairly dumb”. How you want to square that circle I will leave up to you. In my game, it was never encountered. But I think I would have run it as being telepathic, and just very thickheaded.


Assuming you are running Castle Xyntillan in Swords & Wizardry, a final question is what rules to use to handle egoism and control. You could just use the rules in OD&D, or those in B/X (which, note, are different). Me, I found both to be too involved to be used on the spot. I was not alone in this. Paul Siegel, of Wandering DMs, once wrote a nice two-part series of posts in which he looked at “EGO through the ages”, and crunched the numbers on the control check in OD&D to derive a simpler d20-based alternative. This, effectively, is the one I used in Hackbut, my own home-brew rules.

Determine your Will Modifier by adding your character’s Intelligence and Strength and then subtracting from this the sword’s Intelligence and Ego. Calculate your Wound Modifier based on this chart:

Wound LevelModifier
Full hit points+15
≥ Half hit points+10
< Half hit points+5

Roll d20 + Will Modifier + Wound Modifier >= 20 to retain control of the sword.

Paul Siegel. Contested Will Probabilities.

In case it isn’t obvious, I simply use the EGO score listed in Castle Xyntillan as the sword’s full willpower score for purposes of control checks.

Concluding remarks

When I started running Castle Xyntillan I had a copy of the PDF printed at my local print shop and wire bound. This is the copy I used at the table while running the game. I marked up the hell out of it, and the binding makes it lie nice and flat. I also used some post-it note book tabs to label each section of the castle, for easy flipping back and forth. And, as you can see here, I noted the intelligence and communicative ability of each sword in the treasury. Highly recommended.

That’s it. Hope this is of some use to folks out there.