Monday, December 28, 2015

Schrodinger's Lock in Lamentations of the Flame Princess / B/X

For this example, we are playing Lamentations of the Flame Princess (LotFP), though the analysis wouldn't be any different if we were discussing B/X.

The party arrives at the entrance to the dungeon, barred by a locked, wooden door (have we already hit poor adventure design?). Ichabod Salsby, a level 3 specialist, with 1 point assigned to tinker, attempts to pick the lock and fails (rolling a 6 on a 6-sided die).

Under our system, Ichabod may not try to pick the lock again until he reaches the next level. Also, Ichabod's chance to pick the lock was not based on any feature of the lock - he has a 2-in-6 chance to pick any lock in one turn.

Let us construct a model that explains these features. In our fantasy world:
  1. There are a finite number of lock types. Every lock in the world belongs to exactly one of these types, which are all equally probable to occur.
  2. For each lock type, either Ichabod can or cannot pick that lock type - success or failure is automatic depending on type. His tinker skill is a reflection of the number of lock types that he has mastered.
  3. The type of a lock must be determined by a picking attempt. It is not decided by the Judge in advance.
Under this model, prior to Ichabod's attempt, the lock is of indeterminate type. Following the old Schrodinger saw, the lock is of every type simultaneously, until Ichabod's action partially collapses the state of the lock relative to the partition of Ichabod's tinker skill (i.e. the exact lock type is not determined, but only whether the lock is of a type Ichabod can pick, or not).

There are two stubborn facts that contradict this model. First, if Ichabod increases in level but doesn't assign any new skill points to tinker, than why should he be allowed another chance to pick the lock? Ichabod has mastered no additional lock types. Ichabod failed to pick the lock previously because he is unable to pick that lock type, and since he has mastered no additional lock types in his advancement it logically follows that he cannot succeed with another attempt.

Second, allowing Ichabod an independent chance to try a failed lock again after reaching the next level doesn't reflect the true conditional probability of the event. Assuming Ichabod reaches level 4 and places one more point in tinker, his probability of picking the previous lock is now 1-in-4, rather than 3-in-6. The first problem described above is really a special case of this second problem with the model (Ichabod's retry probability would be 0-in-4 rather than 2-in-6 in that case, resulting in automatic failure).

For these problems, I argue that while the model does not perfectly match the mechanics, we have instead a best approximation - to expand the game mechanics to fully match the model would require an unreasonable increase in cost (detail and complexity). The DM would need to track the results of any failed pick attempts and character tinker skill levels over time. The current mechanics match 80% of the model with 20% of the complexity - success.

On the positive side of the ledger, this model explains why:
  • A character may only try to pick a lock once
  • A character may try to pick the lock again after reaching a new level
  • A character with a higher skill may fail, but a character with a lower skill may succeed
  • The chances of picking a lock do not increase with additional time or resources
Part of the reason this combination of model and mechanics works so well in LotFP is because of other mechanics. Lock picking is an improved method of entry (noise, surprise, etc.), but only rarely is it the only method of entry. The characters can always smash the door open with enough time and the right tools. LotFP is very clever in guaranteeing success with a more primitive method, ensuring that no dungeon branch is off-limits due to a bad die roll.

Thursday, December 17, 2015

Consistent Saving Throws in Dungeon Crawl Classics (DCC)


"You burst into the room and find a ferocious Red Dragon. It breathes flame at you. Save or Die!"
-Anonymous 80s DM


A recent post by a contributor to the B/X and DCC google+ communities got me thinking. The claim was, essentially, that DCC Judges seem to pull saving throw DCs out of the air during play - or, worse, that the DCs are chosen for the modules so that they will 'scale' accordingly to the appropriate character level for the adventure (thus creating a treadmill effect). Here are my thoughts on how to make DCC saving throws more consistent, objective, and easier to adjudicate.


Systems like B/X have a tremendous advantage over DCC, in that the Judge simply needs to call for an "X type" saving throw, without having to spend the time thinking over an appropriate target DC. This also prevents the Judge from consciously or unconsciously scaling DCs to character level, creating arbitrariness or a treadmill effect. We will assume as a design principle that we want characters to become objectively better at saving throws as they increase in level.

How do we solve this problem? The first step is to realize that DCC is really no different than B/X, with the exception that target numbers have been switched with bonuses in the class tables, and the rulebook has failed to provide a baseline target DC for saving throws to translate between the two forms. If you run the math, DC 14 as a baseline target for saving throws creates as close to the same arrays as B/X and LotFP as is possible. This is a useful point for people who are interested in converting modules from B/X and LotFP for DCC.

So, for maximum simplicity, the Judge can simply set all saving throws to DC 14. When the judge asks for a Fortitude/Reflex/Willpower saving throw, without specifying any conditions, the DC is 14. If you are converting modules from LotFP, B/X, or other OSR products, also use DC 14.  Alternatively, the Judge can setup a scheme where objective saving throws are called for by descriptor such as:

Easy - DC 11
(default) - DC 14
Hard - DC 17
Critical - DC 20

I like the use of these descriptors because they signal to the players that saving throws have an objective reality - the target numbers will always match up in a meaningful, consistent way with the descriptors, which will match up with like challenges. This is similar to bounded AC in DCC or D&D 5e.

EDIT: After reading through this post again, I wanted to mention that DC 14 is not the "right" answer, so much as one choice for this universal constant of the gaming universe - the choice that most closely matches up with the flavor of B/X and LotFP. You can set the default DC higher or lower according to taste, and by doing that you will be changing the nature of the game that you are playing.

One of the results of an objective system for saving throws is that the Judge only has to account for one variable (result) rather than two (target number + result) when setting challenges for the players. This will usually make things simpler for the Judge when designing challenges for his game.


The number of saving throw categories in the game system is really a matter of taste. B/X and Labyrinth Lord use 5, Swords and Wizardry 1, DCC 3. The more categories there are, the more of an opportunity there is to tweak the arrays for the different character classes to have idiosyncratic highs and lows coming to the same approximate average, and the more of an opportunity there is to target specific categories with bonuses and penalties due to in-game effects. But at the same time, the more categories you have, the more bookkeeping is created, and the more opportunity there is to argue over the appropriate categorization of different events.

Interestingly, with DCC, since the maximum differential between saving throw bonuses up to level 5 (and that is all I'm interested in) is 2 points (10%), there is practically no reason to keep the three categories, with the exception that each category is governed by a different attribute allowing up to a 3 point swing from the baseline. All this being said, I am relatively satisfied with the three categories in DCC - satisfied enough to be defeated by the forces of inertia on this one (though I think I slightly prefer either the B/X or S&W systems, each in their own way). Maybe I just hate the throwback to 3e.

Alternate systems:

  1. Switch DCC to a system where saving throws are directly tied to the appropriate attribute. In this case, they become specially designated skill checks. Provide a single flat saving throw bonus for each character class based on level. At level 5, for all human classes, this bonus would be +2, the average across the three categories. Under this system, there would of course be 6 saving throw categories, one for each attribute.
  2. Completely rip off the saving throw tables of B/X, LotFP, or Labyrinth Lord for the analogous character classes on a level-for-level basis (this is one of the points where DCC does not scale 1 to 2 with other OSR systems).
  3. Switch DCC to a system with a single saving throw, with a single flat saving throw bonus for each character class as with #1 above. Either have one attribute key to saving throws, or simply leave saving throws unrelated to the attributes. Allow for bonuses and penalties to saving throws of a specific type through the use of keywords or descriptive language.

Tuesday, December 15, 2015

DCC Monster: The Songbird

"It would crush its own bones to follow prey down a narrow tunnel."

It doesn't have a name. Garvin was experimenting and came up with a liquid that makes people into something wrong. He kept the first one in a cage, waiting to see how long it took for the creature to die without nourishment. 9 weeks.

It kept running full speed at the bars, beating itself into a pulp, snapping its bones. Then it would lay on the floor, its breath too fast, pulse racing, as the bones and tissue knotted back stronger, more malformed, before it tried again. Garvin reinforced the cage after the first one died - it had almost bashed its way through using only muscle and bone.

Garvin ran so many tests on the first three. He knows the easiest way to kill them, to make them dormant, to transport them. He thinks they are beautiful. He is proud that he invented something so special.

Like other monsters, it doesn't have a name. Sometimes villagers will find a body ripped apart, smashed to pulp, a surprised look on what remains of the face. The people don't know what happened. There are no survivors to talk to. Each village has its own theory, its own name for this.

Only Garvin knows. He calls them Songbirds, because of the sound they make when they look with their ears.

Songbird: Init +8; Atk crush +8 melee (1d4+5) or bite +8 melee (1d10+5); AC 15; HD 6d8+6; MV 40'; Act 2d20; SP blitz, echo-location, regeneration, fearlessness, exceptional strength, immunity to mental effects, SV Fort +6, Ref +6, Will N/A; AL C.

blitz - the songbird attacks ferociously without warning. If it approaches within 40' unnoticed, players must succeed on a DC 14 Int check or be surprised.

echo-location - the songbird has no eyes and senses its environment by echo-location, emitting a singsong call. The songbird tracks prey and other creatures by sound, and has exceptional hearing.

regeneration - the songbird regenerates 1d8 hp/round, one round after taking damage. Acid and fire attacks do not regenerate. The songbird will regenerate even after death, unless it is decapitated or suffers massive damage. Knowledgeable players may spend one round to dispatch a songbird, ensuring it does not return.

fearlessness - the songbird has no concept of fear. It never checks morale, and fights until death. The songbird will use its body as a weapon or ram if appropriate. It would crush its own bones to follow prey down a narrow tunnel.

exceptional strength - the songbird receives a +5 to grapple and other strength checks. The songbird attacks with its crushing hands and vice-like bite.

Saturday, December 12, 2015

Random Funnel Seed Generator

With thanks to the DCCRPG google+ community, I present the Random Funnel Seed Generator. You might use this table to generate ideas for new funnel adventures for your players, or to create the backstory of a new 1st-level character joining the group, assuming they similarly went through a funnel experience "off-camera" (this is my intended use). For my first roll, I came up with a 1, 6, and 12, which gives me:

"A set of clones, created to ensure the survival of at least one copy, find themselves running out of food and supplies, threatening the mission. Out of desperation, the group enters an obvious Negadungeon, forever considered taboo by all who hold to the light. Though the peril was obvious, the group felt they could avoid catastrophe through their own cleverness. They thought the importance of the mission justified their actions. In the end, they unleashed an even greater evil upon the world than that which they hoped to avoid."


Roll Who? Where? What?
1 One of a set of clones created: (a) to ensure the survival of at least one; (b) in a magical accident; (c) as a disposable resource On a bizarre gameshow Guided/tormented by a psychotic AI
2 Street urchins of Ur-Hadad On a derelict spacestation Following an ancient prophecy
3 Desperate slaves, waiting for a lucky break Trapped in a cave system Dinner murder mystery
4 Hopefuls trying out for the circus Lost on an alien planet Hunted for sport by: (a) a rich noble; (b) an advanced alien hunter; (c) unsympathetic humanoids; (d) mutated hillbillies; (e) masked slasher killer
5 Amnesiacs - "Where am I? Who am I?" Out of gas in the middle of nowhere. "Did you hear that?" Doppelganger parasites
6 Group volunteers for a medical experiment Running out of food and supplies. Won't make it much longer. Overrun by giant insects/animals created by: (a) a careless wizard; (b) nuclear radiation; (c) accidentally released from a land of giants
7 Religious heretics, pursued by the Law-Givers of Justicia Ghost Ship/Ship of the Damned/Ship to Hell Oh god no! Not the Pig-Men!
8 Traveling minstrels Woken from Cryosleep Battle to stop the emergence of a Chaos Lord
9 Miners, working for hazard pay Arctic science station Guided by the spirit/hologram of a long dead wizard
10 A group of overmatched pest exterminators Trade outpost out in the boonies The perfect heist gone wrong
11 Lunatics in an asylum Extra-planar battle arena Undead barbarian raiders, "recruiting" the strongest to their army
12 Convicts, scheduled to hang The House on the Hill Entered the Negadungeon, ignored all the warning signs, unleashed a plague on humanity
13 Deserting soldiers, looking for a place to hide Consciousness downloaded into automatons/androids Forced on a mission to rescue the Princess. The Princess is: (a) undead; (b) a willing captive; (c) a robot agent; (d) a grave threat to humanity; (e) currently waging a guerrilla war on her captors
14 Prisoners of war, seeking escape before their inevitable death Solar/Lunar Eclipse "The doctors[/orderlies/servants/guards/children] have been changed into something else, you have to believe me!!"
15 Bored, precocious residents of the Sunset Valley Home for Decrepit Oldsters Ice bridge, three miles long Deathtrap dungeon engineered by Garvin Richrom/The GearMaster
16 Suicide squad offered a chance at redemption Creepy gothic hospital The summoned evil must be bound again, before it's too late. Summoned by: (a) stupid college kids; (b) cultists; (c) one ostracized and forgotten, seeking revenge
17 Imposter heroes (con-men) Shipwrecked on an island paradise Unexpected run in with the undead spider demigod Izzgozz
18 The most ordinary of ordinary peasants Returning from a long voyage, happy to see home again Everyone has mysteriously vanished. Cause: (a) zombie plague; (b) body snatchers; (c) profane flesh golem, as big as a house; (d) Mental domination by the Old Ones; (e) Carnivorous plants that don't leave a trace; (f) hiding from something much, much worse
19 Inheritors of the black sheep's estate Sleepy village in a secluded valley. Everyone seems almost a little too nice Groundhog's Day infinite time loop. For time taken to break out of loop, roll 2d6: (1) 1 day; (2-3) 1 week; (4-6) 1 month; (7-9) 1 year; (10-11) 5 years; (12) 100 years
20 Farmers with failing crops Following an ancient, unreliable map Taken/held captive. Captors are: (a) killed during the prisoners' escape; (b) disabled by natural forces, forcing the prisoners to fight for survival; (c) killed by a stronger force, which the prisoners must deal with

Tuesday, December 8, 2015

The Highest Level in Dungeon Crawl Classics is 5

Marty DiBergi: Why don't you just make ten louder and make ten be the top number and make that a little louder?
Nigel Tufnel: [pause] These go to eleven.
-This is Spinal Tap

Noah Vanderhoff: Zantar is a gelatinous cube that eats warriors in a medieval village, and every time it eats a chieftain you ascend to a higher level. Beauty part is you can't get to the next level, so the kids keep coughing up quarters...[chortles]"
-Wayne's World


The thing you need to realize is that there are no DCC characters above 5th level.

Monday, December 7, 2015

150 Mighty Deeds

DCC Warriors, the world trembles at your approach.

Mighty deeds are not a short list of discrete options for Warriors in DCC. They are anything and everything an action hero could do. They are your ability, once per combat round, to bend the fiction of the game to your will. Use some of the suggestions below, and enjoy watching your Judge become increasingly harried coping with your creativity.

150 ways to crush your enemies:

Sunday, December 6, 2015

Saturday, December 5, 2015

Deity Writeup: Crom

I thought the Carnifex was pretty good.  Let's see if we can do better.  Thanks to Metal Gods of Ur-Hadad and Crawljammer for inspiration.

Crom. The Mountain King. Lord of Valhalla. StarSmasher.

Friday, December 4, 2015

How To Make the (DCC) Cleric Not Suck

"No one man should have all that power
The clock's ticking', I just count the hours
Stop tripping', I'm tripping' off the power
(21st century schizoid man)"
-Power, Kanye

In every system, DCC included, clerics suck. But we can fix them. We can make them Metal. We have the technology. Here we go:

Thursday, December 3, 2015

A Little Light Reading: Sylle Ru's Bookshelf

  1. An Illustrated History of the Western Moorlands
  2. Blackwell's Dieties and Demigods
  3. Astral Travel and You: How to Really Go There!
  4. Artefacts of Yore
  5. The Mystic Ways of the Savage Kings
  6. Property Records - Hirot - 1029-1456