Hackbut – Core Mechanics – Saving Throws

Continuing on my discussion of Hackbut core mechanics, let’s briefly touch on saving throws. This one did not take a lot of poking around. To begin with, I have no nostalgic attachment to the classic saving throw categories. They strike me as obtuse and needlessly granular. I know the origins of the S&W unified save are primarily legal, but they represent a welcome streamlining in my view. So I decided to port them over into the KéK classes. This was a trivial exercise. If you want to do the same, simply use a base save of 15 minus level for fighters and thieves, and 16 minus level for magic-users and clerics. I also use the +2 save bonuses for the various classes as listed in WBFMAG.

That more or less covers saving throws for player characters. One last thing would be how to handle monster and NPC saves. Here, interestingly, WBFMAG and S&W proper diverge. The former has the basic guideline of using 19 minus HD, whereas the latter has a table listing a save value for each HD.

I had problems with both approaches. While convenient, WBFMAG’s monster save seems high in comparison to those of player characters. S&W’s solution requires a table lookup which is a no-go for me. So I decided to do a quick analysis of the S&W numbers and arrived at an average base save of 16 minus HD. Let’s call it a nice and easy to remember 15, incidentally making them save the same as fighters. This means low-level monsters save a little better than by-the-book S&W, and high-level monsters get off ever so slightly worse. I call it a wash.

As an aside, I could have also gone with Delta’s approach to saves, which in many ways is similar in spirit and mathematically balanced to a comparable level as S&W’s solution. The reason I did not go for it is that it maintains the various save categories which, like I said at the top, are just not something I feel I need in my game.

So that covers saving throws. The point of all of this is basically: a unified saving throw is a convenient and justifiable streamlining, easily hacked into your preferred classic D&D ruleset of choice.

Update: Read on for the final of these three posts on core mechanics, discussing ability checks.


Hackbut – Core Mechanics – Attack Rolls

In the previous post I mentioned using Target 20 and Homebrew Homunculus’s simple d20 skill system. I should probably also mention that although I use those basic KéK classes, I did stick with Swords & Wizardry’s unified saving throw. Between the three of them those cover all the “core mechanics” in the game.

I arrived at Target 20 mostly through a process of elimination. I knew I did not want to do any lookups during gameplay so the traditional attack matrices were out. The logical alternative baked into S&W and also WBFMAG is ascending armor class. However, as HH has pointed out, S&W’s base ascending armor class of 10 is mathematically incorrect. You don’t really notice it when you use it out of the box, but I ran into trouble when I tried to come up with a player-facing defense roll that would be mathematically identical to a referee-facing monster attack roll.

This left me with two options: adjust the AACs listed in CX on the fly by 1 point (violating my rule to remain fully compatible with the module), or use descending AC after all. This is when the appeal of Target 20 really became apparent to me. It is both 100% mathematically identical to the original game, and very easy to use at the table. You just need to get over the fact that lower ACs are better.

Incidentally, it is also trivial to rewrite Target 20 as a player-facing defense roll:

Defend: d20 + your armor bonus + opponent attack value + modifiers ≥ 20

Armour bonus: 9 - AC
Attack value: 9 - HD

However, after using this for one session, I came to the conclusion that rolling to attack as a referee is actually faster (and possibly more fun). I’d gotten so used to The Black Hack’s player-facing defense rolls that I thought they were essential to a smooth-flowing game. But the big difference is that attack and defense rolls in TBH are exactly the same procedure, so there is no extra learning involved for players. With my so-called clever defense roll, players now need to learn two procedures. That’s one too many.

This is getting long-ish so I will leave discussion of saves and skill checks to future posts. I’ll just reiterate that Target 20 is indeed the superior procedure for attack rolls in classic D&D. I recommend using it.

Update: Read on for details on how I do saving throws.


Hackbut – Overview

So, let me tell you about my D&D hack.

I put this together for my Castle Xyntillan campaign. After a 30+ session campaign using The Black Hack I decided I wanted to try a ruleset that would be closer in feel to Original D&D. In particular, I had grown weary of the roll-under ability score mechanic. What I did like about TBH, and continue to appreciate, is its simplicity and accessibility. So whatever I would switch to would ideally be of a similar level of complexity.

The obvious choice would have been Swords & Wizardry, because that’s what the megadungeon is ostensibly written for, although I believe Gabor Lux used another system to play-test it, and there are a few details, like intelligent sword stats, that don’t show up anywhere in S&W. But I wanted something a bit more light-weight, while at the same time maintaining full compatibility with the module’s contents.

I also considered using Old-School Essentials, but although its presentation is incredibly slick, believe it or not, I still felt it comes with overhead that I would then have to house-rule out. I wanted to be able to have one document that would contain all of the rules.

So, I decided to put together a full-fledged hack of my own. The trigger, if I recall correctly, was reading the Kazamaták és Kompániák basic classes. I really liked the level 6 ceiling on those. It nicely matches the level range of CX and I prefer a low-level game anyway.

Not feeling like re-inventing the wheel, I looked around for a game to use as a chassis. Ultimately I went with White Box: Fantastic Medieval Adventure Game. It’s small but comprehensive, and therefore makes for easy copy-pasting and adapting.

So those are the two basic building blocks of what is now titled “Hackbut”, my classic D&D rules kit-bash: WBFMAG provides the rules framework, and KéK provides the classes, although I did overwrite quite a bit of both. Other key elements include Delta’s Target 20 for attack rolls, and Homebrew Homunculus’s simple d20 skill system for, well, most all other situations that need resolving through dice.

There is a lot more to be said about the various components that make up Hackbut, but I’ll leave that for future posts. The point here was mainly to say that if you are in the mood for putting together your own D&D hack, consider picking up WBFMAG. It’s an excellent place to start if you want something that is fully compatible with the old editions but easily adaptable.

Update: Read on for the first of three posts on Hackbut’s core mechanics, on attack rolls.

Actual Play

Castle Xyntillan – Session #1 – Off to the Races

The Company:

  • Marredorn (F1)
  • Fernando (T1)
  • Anna (F1)
  • Mattia & Giulia (bowmen)


  • Mattia — fried by a razzle-dazzle’s lightning bolt


  • Flask of fortified wine
  • Bag of dancing beans
  • Mysterious metal wand


We resume last session’s action immediately after the death of Iacopo at the hands of a couple of skeleton guardsmen. Marredorn’s bowman Mattia holds it together, merely raising an eyebrow at the sight of Iacopo’s corpse. Bowman Giulia, who was in the employ of Iacopo, loses her cool and requests she be let go. An argument develops and culminates with Anna hitting the bowman with her mace to make her point, to which Giulia responds by high-tailing it out of there.

The company continues their exploration of the courtyard. They make their way to several buildings attached to the interior of the castle wall. Fernando cautiously peeks through a bunch of murder holes and is surprised to see a hammer work at an anvil of its own accord, in what appears to be a smithy. They sneak through a door in an adjacent structure and find themselves in a stable. A search of the stalls does not uncover anything except debris crawling with gross bugs. Searching through the hayloft does turn up a flask of what appears to be a wine-like substance.

A door leading off from the stables is cautiously opened and peeked through. It opens on what appears to be a barracks where a bunch of skeleton guardsman are using the plate-clad corpse of an adventurer hanging from the rafters for target practice. Managing to remain unseen, the company quietly closes the door again on this grisly spectacle, and makes their way out of the building.

Back in the courtyard the company scale parapets and enter a tangled rose garden. The heady smell of the roses makes them drowsy and they spot decaying limbs writhing in the flower beds. Not wasting any time they quickly force open a door leading into a tower and are somewhat surprised to find it has been converted to a gardener’s shed. A search of the shed turns up nothing noteworthy except for a bag of beans that appear to jump and dance of their own accord. The bag is secured to a cask with some twine and the company continues on through a door into an empty hallway inside the castle wall. The door at the other end leads into one of the gatehouse’s ruined towers. They find nothing of note.

The company makes their way back to the shed, grab the bag of beans on their way out, and nervously cross the rose garden to the door on the other end that appears to lead into the castle. It opens onto an empty room. Fernando cautiously inspects one of the doors leading off from it and hears the sound of galloping horses. Carefully peeking beyond the door he sees a hallway strewn with smashed furniture and a thoroughly trampled corpse. Two ghostly horses speed past, one seemingly made of a bright light, the other of dark clouds.

Horses can be a problem (John Steuart Curry)

The company decide to try another approach. They enter another empty room and from there move into a room filled with rotting banners decorated with Malévol heraldry. After a search of the room they move on and open a door onto a hallway where a weird wind continuously pushes and pulls on them as they stand in the doorway. They shut the door and try another one. This leads into the same hallway where they spotted the phantom horses earlier. From this vantage point they can see several doors not too far down the hallway.

Marredorn volunteers to make a run for one of the doors. He waits for the horses to pass and sprints towards it. To his dismay it is locked not once but twice. Barely keeping it together while the horses fast approach he bashes into a door across the hallway and stumbles into another passage, this one strewn with withered leaves.

The remainder of the company take turns rushing across the hallway to rejoin Marredorn. After briefly debating some way of cracking the locks on the mystery door they decide to try their luck elsewhere instead. Turning a corner in the leaf-strewn hallway they bump into two headless manservants. Both parties confusedly observe each other until Anne boldly commands them to go into the phantom horse hallway to clean up the terrible mess it contains. Impressed by the fighting-woman’s show of authority, the manservants pass the company by and exit through the door into the hallway. Not much later, the crunch of manservants trampled by horses can be heard.

The company continues down the leaf-strewn hallway. Three doors lead north, east and south. They take the south door and enter a bedroom in disarray. Beans have collapsed into the room, the statue of a robed man has been knocked from its pedestal, and a large pile of leaves lies in front of an impressive painting of an autumnal park scene. The room is searched. When Marredorn replaces the statue, it comes to life and offers him a metal wand. He accepts the offer and the statue returns to normal. After taking a moment to loudly ask themselves what in the world just happened, they turn their attention to the leaf-pile. It is prodded with several implements and a massive mound made of moss and vines rises from it. They stagger back but the thing does not pursue. The company gingerly backs out of the room, and closes the door.

Losing her patience, Anne decides to make a run for the locked door back in the galloping hall. She smashes a lock with her mace and knocks it clean off. Just when the horses are about to trample her she dodges back into the leaf-strewn hallway. Although successful, it turned out to be a closer call than she liked and so she decides against going for the other lock as well.

The company goes back down the hallway and opens the east door at its end. Beyond is a hallway with curtains of moss hanging from the rafters. Deciding they need less plant matter, not more, they close the door and open the north one in stead. It opens on a small room filled with toadstools, and five clusters of flickering lights floating above it. Before they can close the door on this eery sight both Marredorn and Mattia are assaulted by the entities with lightning bolts. Marredorn barely survives the attack and Mattia collapses. Their companions drag the bowman’s lifeless body back into the hallway and Marredorn slams the door shut.

We leave the company there, standing in a leaf-strewn hallway, with the fuming body of poor Mattia lying at their feet.

Referee Commentary:

Our first full CX session did not disappoint. Play moved at a fair clip and some tense and interesting situations developed. The main pleasure for me as a referee is that I honestly can’t predict which way players will go, can’t really read ahead, and therefore am almost as much surprised as they are by the things that transpire.

We had a significantly smaller party with no spell-casters this time around. Our group consists of seven players and we game once a week. Who can make it to any single session varies from week to week, which I don’t consider an issue so long as we have a minimum of three players.

The only real question is with multi-session expeditions, how to handle absentee player characters, or characters joining mid-expedition. In our previous campaign we tried various approaches to this, but ultimately settled on just hand-waving it and having characters pop in and out depending on if their player is present. It’s a minor knock against verisimilitude, but the overhead introduced by most procedures for mitigating it just isn’t worth it for us.

I’d pre-rolled a bunch of random encounters and diligently checked for them at the top of every exploration turn. I also made reaction rolls for everything except when the encounter description clearly stated what a monster’s disposition would be. I believe this applied only to the phantom horses and the razzle-dazzles. I particular enjoyed the scene with the headless lackeys. Anna’s player intuitively grasped a way to resolve it with some bluffing and I just let them succeed.

They started the game with two retainers and ended with none. One was lost at the start due to a failed loyalty check, the other at the very end expired from a monster’s attack. I wonder if they’ll press on or cut and run. I guess there’s only one way to find out.

Actual Play

Castle Xyntillan – Session #0 – A Halberd to the Back

The Company:

  • Heinz (MU1)
  • Robain (C1)
  • Marredorn (F1)
  • Fernando (T1)
  • Guillemette (T1)
  • Iacopo (F1)
  • Luna (light bearer)
  • Isabel, Raul & Michelle (porters)
  • Mattia & Giulia (bowmen)


  • Iacopo — chopped in the back by skeleton guardsmen


  • Bejeweled snuff box
  • Perfume bottle


Our freshly minted company of fortune seekers find themselves at the gates of Castle Xyntillan on the morning of Wednesday, September 27, 1525. Briefly considering their options, they decide against first exploring the castle perimeter and choose to cross a bridge over a muddy moat and barge straight through a ruined gatehouse. A flock of ravens quietly observes them from the parapets.

They find themselves in a destitute garden. To the north an island pavilion in a small lake piques their curiosity. Heinz, Iacopo and Robain wade across and discover the pavilion contains a grave marked with the name “Tristano Malévol” and four hands. Heinz and Iacopo shove the lid aside while Robain stands at the ready brandishing cross and stake. They are greeted by the sight of a four-armed skeleton dressed in ragged courtly attire. It awakens with a cackle and responds with chagrin to the sight of the cleric’s holy symbol. When its request for the adventurers to leave it in peace is met with hesitation, it lashes out at the magic-user with its four claws. Before it can do any damage it completely disintegrates in response to the clerics’s vigorous preaching. A hurrah rings out across the silent pond. The trio searches what remains of the creature for treasure, pockets a snuffbox, a perfume bottle and a dried rose, and wades across the lake to rejoin their companions.

The company continues their search of the courtyard. While Robain pokes around the vegetable patch, Iacopo wanders off towards two brightly painted guardhouses in poor repair. He spots two skeleton guardsmen, both armed with halberds, apparently snoozing on the job. Iacopo turns to return to his companions but is unaware of the skeletons quietly pursuing. Before his companions can intervene one of the halberds strikes home, dropping the fighter to the ground. A flurry of bolts and arrows from the bowmen and Marredorn make short work of the skeletons. But the damage is done: Iacopo has expired.

Welcome to the castle (Christian Degn Petersen)

Referee Commentary:

  • The majority of the session was taken up by character creation, a rules overview and some session zero questions. Some time was also spent on acquiring retainers. So we did not get in as much actual play as we normally would, but it was still an atmospheric and action-packed start to a campaign I have been looking forward to kicking off for some time.
  • The outright destruction of Tristano was due to a very lucky roll by Robain’s player. We are using turning rules by Brendan over at Necropraxis. Succeeding by 5 points or more on a d20 against 10 + the undead’s HD means they are destroyed. Tristano is a 4HD undead. They rolled a natural 20. There you go. Otherwise they could have had a pretty bad time fending off the skeleton.
  • Conversely, Iacopo met his demise due to a combination of careless play and bad rolls. I felt a little bad about this afterwards because the encounter happened when we were already pushing our usual stopping time and we were all a bit tired and prone to mistakes and bad decisions. I made a hidden roll to see if Iacopo would remain unnoticed, and failed the roll. Iacopo then rolled for surprise when he was being stalked by the skeletons and also failed. Because his companions were able to warn him I allowed a roll for initiative anyway, and they failed that roll as well. So the skeletons got to attack first, one hit, and I rolled 8 on the 1d8 for the halberd, enough to fell most level 1 fighters. Finally, they failed their death save, and that was it. My only real regret is that I forgot to make a reaction roll for the skeletons. They may not have attacked immediately. It’s a habit I still have to develop. I also go back and forth on hidden rolls for stealth and such. After this experience I’m inclined to go back to rolling everything in the open, even if that spoils things sometimes. It just doesn’t feel right to spring things on my players in this way. It verges on “gotcha” GM’ing which I strongly dislike. The book also has details on the skeletons, which upon reflection should have made it harder for them to wake up. But because of the hour and my fatigue I forgot all those things. For all these reasons I gave Iacopo’s player the option of making his death save after all. But being the good sport they are, they declined the offer, and the party will be rejoined by a newly rolled up fighter on the next session.


20 Quick Questions: Rules (Hackbut)

Answers to Necropraxis’s 20 questions about the rules of my upcoming Castle Xyntillan campaign. I’ll be using a kit-bash of rules mostly from OD&D and B/X (largely via Swords & Wizardry and Old-School Essentials) which I’ve dubbed “Hackbut”.

  1. Ability scores generation method?
    3d6 down the line, swap two
  2. How are death and dying handled?
    Save vs death at 0 hp, success means you are unconscious and at 1 hp, failure means you’re dead.
  3. What about raising the dead?
    The raise dead spell is in play, and handled as per old-school essentials (OSE) OD&D. It’s a 5th level cleric spell, which means you would need to find a cleric of sufficiently high level to cast it (7th level) which is unlikely anywhere in the immediate area of the campaign. However, the dungeon also contains a very small number of items that can raise someone from the dead…
  4. How are replacement PCs handled?
    It’s recommended to bring a few retainers — these can easily be promoted into a class by assigning 250 gp worth of treasure to them if they are 1HD. 0-level “normal humans” (non-combatants) require an additional 125 gp 1000 gp. Any other replacement PC can be rolled up and can join the party at the earliest possible moment.
  5. Initiative: individual, group, or something else?
    Individually rolled each round, winning initiative means you act before the opposition, losing means you act after.
    Group; roll 1d6 at the top of each round, on a 4-6 the PCs go before the opposition.
  6. Are there critical hits and fumbles? How do they work?
    Crits do max double damage. Fumbles give the opposition a free attack or might cause some other mishap which requires an action to recover from.
  7. Do I get any benefits for wearing a helmet?
    Helmets are assumed to be part of any armour worn. No specific benefits.
  8. Can I hurt my friends if I fire into melee or do something similarly silly?
    Yes, target hit when firing into melee is determined randomly, odds possibly adjusted for relative size.
  9. Will we need to run from some encounters, or will we be able to kill everything?
    Running will more than occasionally be a wise decision.
  10. Level-draining monsters: yes or no?
    No. Undead drain attributes. Hitting 0 in an attribute means you’re lost and become undead yourself.
  11. Are there going to be cases where a failed save results in PC death?
    Yes. Save-or-die is on the table.
  12. How strictly are encumbrance & resources tracked?
    Pretty strictly, but abstracted into a slot-based system.
  13. What’s required when my PC gains a level? Training? Do I get new spells automatically? Can it happen in the middle of an adventure, or do I have to wait for down time?
    No requirements other than returning to a safe haven and spending roughly a week of downtime there. Spells are acquired automatically at level-up.
  14. What do I get experience for?
    XP is gained by recovering treasure, and by spending treasure frivolously carousing.
  15. How are traps located? Description, dice rolling, or some combination?
    Primary means of locating traps and other secrets is through description. Dice rolls are used when outcomes are uncertain or when a player insists they want to expedite things and handle them abstractly.
  16. Are retainers encouraged and how does morale work?
    Retainers are encouraged and probably necessary to be successful, given the somewhat limited carrying capacity of characters. Each retainer has a morale rating which is rolled against when things get dicy. Failure means the retainer would very much like to terminate the expedition. Morale only ever goes down. (For more details see the rules in Castle Xyntillan.)
  17. How do I identify magic items?
    The primary means is to empirically test the item yourself, or convince some hapless retainer to do it for you. NPCs in town are able to identify potions and items for a fee.
  18. Can I buy magic items? Oh, come on: how about just potions?
    Some magic items and potions are for sale in town.
  19. Can I create magic items? When and how?
    Yes, you can. It will cost a significant amount of time and money, and might require specific ingredients or components for which a quest is needed.
  20. What about splitting the party?
    Good luck, have fun.

Updated 15 September 2020.