I must create a system, or be enslaved by another man's. I will not reason and compare: my business is to create.

- William Blake

Friday, December 23, 2016

Roll xd6 under ability: yet another D&D skill system

I promise: this is the last skill system for OD&D / BX D&D I write about this year!

(Not quite the first one, though....)

So, here is the thief table skill from BX, with one very good and easy solution for people that prefer a more unified skill table, from Tales of the Grotesque and Dungeonesque (source):

This solution is not only easy and elegant, but also answers the question "what about other classes" (answer: 1-in-6 for everything), and makes the thief better than everybody in this regard, which is essential. LotFP does something similar.

There is at least one different solution it you want things to be a bit fiddlier.

James V West (Doomslakers!) posted this to G+ a few hours ago (from D&D Companion set, book 1, page 9; click to enlarge):

It is an interesting bit, and contains a variation of Moldvay's "there is always a chance". Here is the relevant part:

But would that work with thieves' abilities? Let us try with 4d6 (the numbers are form anydice.com):

Roll %
4 0.08
5 0.39
6 1.16
7 2.70
8 5.40
9 9.72
10 15.90
11 23.92
12 33.56
13 44.37
14 55.63
15 66.44
16 76.08
17 84.10
18 90.28
19 94.60
20 97.30
21 98.84
22 99.61
23 99.92
24 100.00

You have 15.90% chance of rolling 10 or less with 4d6. Try this: add thief level to any ability, Assuming the thief has 10 in any given ability, you would have to roll under 10+level with 4d6 to succeed. These would be your chances:

Level %
1 23.92
2 33.56
3 44.37
4 55.63
5 66.44
6 76.08
7 84.10
8 90.28
9 94.60
10 97.30
11 98.84
12 99.61
13 99.92
14 100.00

Close enough? The thief becomes a bit more competent overall, which isn't a bad thing IMO. The chances are even better if the thief has a high ability score. You might use Dexterity for stealth and picking locks and Wisdom for hearing noises, thus "customizing" each thief without needing different tables. Or just use 10+level for everything if you want things to be simpler.

The problem is that 100% there; you see, there is always a chance of failure in the original rules, and I kinda like that. What if we chose a single one of the die to explode, i.e, add another die if you roll a 6? This is probably too fiddly, but the results are quite pleasing: a level 10 thief with Dexterity 15 would still fail 2% of the time, and a level 14 thief with Dexterity 18 would still have one chance in a thousand of failing (there is always a chance!).

(Level) Roll %
4 0.08
5 0.39
6 1.16
7 2.70
8 5.40
9 9.65
10 15.60
1 11 23.21
2 12 32.21
3 13 42.12
4 14 52.21
5 15 61.79
6 16 70.35
7 17 77.56
8 18 83.30
9 19 87.65
10 20 90.88
11 21 93.25
12 22 94.99
13 23 96.28
14 24 97.25
25 98.00
26 98.57
27 99.00
28 99.32
29 99.56
30 99.73
31 99.85
32 99.92

Even closer to BX! Compare it to the open locks progression. BTW, "the obvious solution is to just use open locks as a generic "chance to perform any thief skill" as you can see here (post #232).

This also "solves" climbing, by the way. Just use 2d6, since if is apparently easier than any other thief skill:

Roll %
2 2.78
3 8.33
4 16.67
5 27.78
6 41.67
7 55.56
8 67.13
9 76.39
10 83.33
11 87.96
12 90.28
13 92.59
14 94.52
15 96.06
16 97.22
17 97.99
18 98.38
19 98.84
20 99.23
21 99.54
22 99.77
23 99.92
24 100.00

So, 2d6 for easy stuff, 3d6 for ordinary things, and 4d6 for specific skills such as picking locks, hearing noises, etc. 5d6 for truly legendary feats.

From then on, you can add a few skills to other classes, explore different abilities (maybe the strong fighter is a better climber than the thief at level 1 - now every point matters), add specialties (roll one less dice if the PC is an expert), mess around with fractions, and so on. Backstab? Got you covered.

Source - xkcd. Like you didn't know.
So, now I have, what, half a dozen skill systems for B/X? All because I wanted a single one... Yeah, I guess that is how it goes.

Sunday, December 18, 2016

12 ways to recover your dead character's XP

Sometimes I play with the idea of creating a system where PLAYERS, not characters, gain XP for their adventures. Character death would not only be expected, but an important source of XP. The point is that there is continuity to the campaign even if not for all the characters. Or play around with multiple characters, POVs. Anyway, I didn't go too far with it, but this table might useful for somebody.

12 ways to recover the XP of a fallen character

When a character dies, his XP can be recovered automatically or though different actions, at the percentages described below. If more than one person receives the XP, it is divided equally or according to GM's decision. For example, if 10% of the XP is distributed to immediate family, the GM might decide everyone gets an equal share, or that a smaller share goes to a bastard brother that lives somewhere else, if he qualifies.

The total isn't important - maybe only 30% of the XP is recovered, or maybe 110%; it doesn't matter, as long as the death doesn't create more than 100% XP without any effort. Also, you might limit the XP to avoid the deceased's allies get more than half the XP his enemies get for killing him.

Or just roll a d12 instead.

By the way, inheritance rules from OD&D still apply.

1. He died so we could live. If the deceased risked his life for the purpose of saving someone, whoever was saved get 20% of the XP.
2. Survivor. If 1 doesn't apply, 10% of the XP automatically goes to anyone who survived the same event (peril, battle, creature, etc) that destroyed the deceased;
3. For Gondor! 10% of the XP automatically goes to one single organization (realm, criminal gang, guild, etc) the PC was part of, preferably one that was involved in the affair; if the PC screamed the name of the organization ("For Gondor!") right before dying, make it 20% of the XP.
4. Blood is thicker than water. 10% of the XP automatically goes to immediate family.
5. Political history. 10% of the XP automatically goes to anyone who is aligned to any historical movement the deceased was somehow part of; the fall of an empire, the rise of a great family, etc.
6. Cosmic Forces. 10% of the XP goes to people or gods of the same alignment than the deceased.
7. Requiescat in pace. 10% of the XP goes to the ones who take responsibility for retrieving the body and giving it a decent burial.
8. In memoriam. 2 to 20% of the XP is distributed among those who build a decent memorial for the deceased - a tombstone, a statue, plaque, naming something after him, etc.
9. Speak of the dead. 1 to 10% is distributed among those who first mention the deceased in casual conversation not related to the death itself.
10. Revenge shall be mine! 10% of the XP is distributed among those who try avenge the deceased the moment they make a vow of vengeance. Breaking this vow has dire consequences...
11. The spirit lives on. The GM can give 10% XP to someone he deems an spiritual sucessor to the deceased.
12. Deathbed promise. 10% of the XP is distributed among those who vow to fulfill the most important wish of the deceased, and succeed in doing so.

Sunday, December 11, 2016

Stacking advantage/disadvantage in D&D 5e

Like many people, I am fan of the advantage/disadvantage mechanic in D&D 5e (click here if you don't know how this works). So much, in fact, that I've added it (albeit in a modified form) to my own RPG.

What I don't particularly like is how ad/disad doesn't stack. I understand the reasoning - let us keep this simple - but the results are often unsatisfactory for me.

Fortunately, someone has already "fixed it" for me.

To understand why this is a problem for some people, let me paraphrase the author's description of the problem:

"I have higher ground, the enemy is blind, bound, prone, and I have a magical effect enhancing my attack!" ...But only one advantage is accounted for? 

Okay, I added "bound" and "prone" for effect, but you get the idea. In fact, this didn't quite happen to me, but what did happen was a bit worse - although less obvious.

The gist of it is that I had built a character with a special strength against a certain enemy - my nemesis, so to speak. When I finally confronted him, I immediately used some power to give me advantage (although I don't remember which), since he was a "final boss" of sorts.

But I had info on my enemy. I had studied his habits, weaknesses, etc., and so when he attacked I used his weaknesses against him. It was an epic moment when he fell for my trap! And them the GM said.... "You have advantage to attack him for the rest of the combat"!

Which means: nothing.

You see, the GM gave me the opportunity to try my plan and decided that it had succeeded; he gave me advantage not to mess with me, but because he didn't realize I already had it. But even if he did, what else would he do? This is how D&D 5e works, RAW: if the player comes up with a clever tactic or puts himself in an advantageous situation, etc, he gets advantage.

I won't get too deep into the "why four advantages shouldn't be negated by one disadvantage". Four advantages and one disadvantage should mean three advantages. This is just common sense to me, but you might prefer to play RAW.

Anyway, the link above has a couple of fine solutions for the problem.

The first one is obvious: roll more dice. That works well enough, and although it messes with the probability of getting a critical, I don't think the Champion will suddenly become overpowered because of that.

But I like to avoid both messing with the game's assumption about critical AND rolling dice pools, which don't quite fit the way I play D&D.

The second solution is also good: +1 for each advantage after the first.

I have very a similar one, that I find a bit easier and better.

First, let me show you the numbers. This is the average roll for multiple d20s. The graph is form the same link above:


1d20: 10.5.
2d20, pick highest: 13.82
3d20, pick highest: 15.49
4d20, pick highest: 16.48
5d20, pick highest: 17.15
6d20, pick highest: 17.62...

Did you notice a pattern here? When you have 2 advantages, you gain a bonus of roughly +2 to your average when compared to one advantage. With 3 advantages, the bonus is close to +3. You can say you get a +4 bonus if you have 4 advantages, but that is pushing it, and the system breaks after the fifth advantage. But I reckon having five or more advantages at once will be very rare indeed...

To make it short:

If you have more than one advantage, roll two dice and pick the highest as usual, but add the total number of advantages to the result: +2 if you have 2 advantages, +3 if you have three, and +4 if you have four or more.

I like this system both because advantages get progressively less meaningful, and because having a second advantage is still a significant (+2) bonus, specially against high DCs. Two advantages, in fact, is the most common "problem" this rule is trying to fix: since you can often get one from your character sheet (which shouldn't be the entirety of your character IMO), it is nice to be able to get a second one through tactics, circumstances, and so on.

Wednesday, December 07, 2016

How to run NPCs in combat (Days of the Damned, D&D and all RPGs)

I have been recently discussing the subject on multiple forums. The context is usually D&D 5e, and the questions are:

- Should the NPCs attack the wizard first, since he might have lower AC and some good area attacks, or deal with the raging barbarian first? Are they even sure the old guy in robes is a wizard?

- Does the paladin need some kind of "Defender" role to "mark" his foes so they don't attack anyone else, or do the enemies attack the big armored guy first anyway?

- Should my fighter have an opportunity to use his Polearm Master and Sentinel feats, or are all enemies intelligent enough to assume everyone holding a halberd has such talents and therefore shouldn't be approached?

For me, any answer that ruins the fun of the classes and feats (or makes them useless) are not good enough. When in doubt, let the PCs be awesome. Now, if the PCs repeat the same tactics over and over again in the same fight, is obvious that the enemies will avoid it; not only because it makes sense in character, but also because it gets boring after a while.

In any case, I am currently finishing the "GM's Guide" for Days of the Damned, my "new school" RPG (okay, "middle school", maybe), and I thought this excerpt might be useful for D&D players - or for any RPG, really.

Let me know what you think!

This guy can be ANY class. Check the PHB!
Chapter 5 - To Rule in Hell [excerpt]
Controlling NPCs in a fight can get tricky. The GM will often manage multiple characters at once, while dealing with a new set of traits and powers in each combat and trying to keep things interesting and fresh at the same time. Here are a couple of tips that can help you out.

When to fight
First, remember NPCs will not enter a fight they cannot win unless they have a very good reason to do so. In fact, even when they know they will win, the fear of death and injury will keep most people (and animals) from fighting without a purpose, specially when they can get what they want by negotiating, begging, or running away (even if they want to fight another day under better circumstances).
Of course, a few fights might be unavoidable. Some NPCs are just too honorable, stupid, desperate or bloodthirsty to look for better alternatives. Many will fight to protect an important place, person or possession, but few are willing to risk their lives for that, unless fighting for a focus.
The damned will often fight for no reason, but even they will negotiate if the circumstances are unfavorable for a fight.

How to fight
When you control NPCs in a fight, you might feel compelled to think of them as moving pieces, and play them tactically as if you were playing a game of chess against the PCs. Avoid this urge.
Each NPC has its own capacities, knowledge and goals. Remember, most NPCs know nothing about the PCs and their powers, even if the GM does. Do not fall into the trap of assuming the NPCs will always come to the right conclusions. “The old guy with a staff is probably a sorcerer” is an uncommon assumption – instead, he is most likely someone that needs a walking aid (at least until he casts a spell).
Once the PCs start fighting and using their abilities, some things will become obvious, and NPCs will react accordingly. Still, most NPCs will not be able to see the whole picture at once. One easy way to dealing with this is assuming most NPCs will attack whoever hurt them most (individually, not as a group) since their last turn, unless they have a reason to do otherwise.
A good leader or tactician can change everything – he can order the other NPCs to work as a group, making the best choices for their side even if he needs to sacrifice a soldier or two. A good plan will make NPCs ten times more dangerous, at least until the plan is derailed. A careful study of the PCs tactics will give the NPCs an edge (and vice-versa).
In short, play NPCs not as pawns, but as people. Intelligent, experienced NPCs will fight intelligently, bestial NPCs will fight instinctively, and stupid NPCs will often make dumb mistakes.

When to stop fighting
Even if the NPCs do get into a fight, they are not necessarily fighting to the death (fighting for a higher focus might be the exception). Most people will surrender or flee after a major wound, unless their side is obviously winning, and even then, they will give up after a second major wound. This cuts both ways – most NPCs will accept surrender and will stop fighting as soon as they get what they want.
Once again, the dammed, the corrupted and the insane are more likely to fight to the bitter end.

All images copyright of Wizards of the Coast.

UPDATE: this eventually became an entire chapter in Teratogenicon. Check it out!

Wednesday, November 30, 2016

Crits are fun, fumbles are... funny

D&D has a popular rule (or house rule, in some editions) that states that a "natural 20" means some kind of critical success ("crit") - maybe maximum damage, or some exceptional outcome if you're testing a non-fighting skill. The current edition only uses it in combat, so let us talk about that

Crits aren't really needed to run the game, but they are certainly fun for many people, and they have become so natural (pardon the pun) to D&D that even people who don't play RPGs might be familiar with the concept (from the numerous internet memes about the subject).

Using the "natural 20" rule causes some odd outcomes - if you only hit on a natural 20, all your hits will be critics, which sounds a bit strange. Also, when you compare two fighters of different levels, the lesser one will get critical hits as often as the better one, but a bigger percentage of his hits will be crits (both will crit 5% of the time, but the worse fighter may crit once every two or three hits while while the better one will crit once every ten or more hits). This means that the worse fighter will cause more damage per hit, in average, although he will hit less often.

Not that it really matters - it is all quite abstract anyway - but it does bother some players. In any case, there are plenty of solutions to "fix" this problem.

The most irritating solution, in my opinion, is the one 3.x / Pathfinder uses:

"When you make an attack roll and get a natural 20 (the d20 shows 20), you hit regardless of your target’s Armor Class, and you have scored a threat. The hit might be a critical hit (or "crit"). To find out if it’s a critical hit, you immediately make a critical roll—another attack roll with all the same modifiers as the attack roll you just made. If the critical roll also results in a hit against the target’s AC, your original hit is a critical hit. (The critical roll just needs to hit to give you a crit. It doesn’t need to come up 20 again.) If the critical roll is a miss, then your hit is just a regular hit. 

A critical hit means that you roll your damage more than once, with all your usual bonuses, and add the rolls together." (source)

I think this kind of thing is what made me believe 3e was too complicated when I was busy playing GURPS (and GURPS has its own version of this, only slightly less horrible). So you roll once, get a natural 20, then you roll again to see if that is a critical hit or not (nothing happens! Yay!), and then you roll again for damage (and if you roll low, gratuitous disappointment once again!).

If you're using crits, they are supposed to be FUN (or, really, why would you use them?); rolling dice for no reason is not fun in my book, and getting excited with a roll only to be disappointed in the next moment seems like a terrible idea (which is why I think there should be no "nothing happens" entries in critical hit tables).

"A natural 20 means maximum damage" sounds way better in comparison. Also, "a natural 20 means you get an extra attack" is such a better alternative that sometimes I'm amazed this "threat" thing is used at all - the numbers are similar enough so it doesn't become a problem (trust me, your fighter won't outshine the wizard), you get a treat (not a threat!) even if your foe has 1 HP left, and the whole scene gets some extra action even if you miss the second attack!

(Yeah, I do realize that there are people that like their weapons lists looking like this. It is all "more damage" to me, and at this point I would be rather using 1d7 weapons or re-rolling 1s if I wanted this level of granularity. But, really, special effects are much more fun for me)

If you want the better Fighter to have even better crits (without special feats or powers), try combining the two: A natural 20 means maximum damage, AND you get a new attack immediately. If you want to encourage creative tactics, the second attack must be different form the first one; maybe a kick, off-hand weapon, head-butt, shield bash, a different target, etc; or you can trade the damage from the first attack for an attempt at disarming, and so on.

This way, you get your prize immediately but you ALSO get the chance of a bigger prize. A natural 20 is always better, so everybody can be excited after rolling one, but the better Fighter gets better chances to be even more awesome (extra damage or some special effect).

Of course, critical hit rules make combat a but more unpredictable and dangerous, which is a good thing in my book, but maybe not for everyone; a 1st level Fighter might be able to bring down a 3rd level one in a single attack, for example.

Fumbles (the idea that something incredibly bad or embarrassing would happen to the character when a "natural 1" is rolled) on the other hand, are a bit double-edged. They can certainly be funny, I guess, and they have their own memes, but they never really worked for me. Fortunately, most D&D editions that I have played (including 5e) do not use this rule, although it might be a popular house rule.

In addition to the whole problem of competent Fighters fumbling as often as 1st level ones, most editions of D&D give multiple attacks to high level fighters - making them fumble MORE OFTEN than low level ones, almost once every two or three rounds depending on the specifics.

Even the "on a natural 1, you have to make a Save vs. X or lose your weapon" is not always enough to offset this effect; it also brings us back to "roll to see if anything happens" problem.

Besides, fumbling 5% of the time is a bit too much. If you think of critical hits as head shots, knockdowns, tripping, etc, you will se that this happens quite often in MMA fights, movies, books etc. But how often do people throw away their own weapons or fall to the ground due to incompetence or bad luck in the kinds of adventures that have inspired D&D? Can you imagine Elric or Conan doing something like that?

Fumbles are bad even when NPCs do it. How heroic is winning a fight because your adversary stabbed himself by accident? Finishing a battle this way is more anti-climatic than rolling again to find out that nothing happens.

In short, fumbles are mostly a comedic device. Nothing wrong if that is what you're looking for - I certainly had my laughs while "tripping in invisible turtles" when playing Rolemaster.

Still, I see at least one interesting use for "natural ones": as a risk-reward mechanic. This means that the natural 1 only matters when you take an exceptional risk. For example, if you want to jump down from a house over you enemy and stab it as you fall.

Fortunately, 5e has a good multi-purpose mechanic to go with it: advantage/disadvantage, which opens up all kinds of possibilities, specially "bittersweet" results. Here are two examples:

- Disadvantage: when you have disadvantage, the fumble only happens if both dice are natural ones, at it is probably related to what caused disadvantage in the first place (you fall if the ground is slippery, you stumble if you're fighting in the dark, etc). Fumbles will be frequent, but easy explained and not necessarily ridiculous.

- Advantage: if you take a significant risk to get advantage (jump from a tall house over an unsuspecting opponent), a double 1 means you fumbled. In addition, the GM will choose one of two possibilites before you roll:
* Make a natural 1 in any dice cause a fumble, no matter if your hit your target or not (fumbles will be frequent regardless of skill, but will not affect your chance of success).
* Ask you for some kind of a skill roll to avoid the risk, no matter if your hit your target or not.

Regular roll: there are no fumbles unless you take some significant, uncommon risk before you roll. Ordinary actions shouldn't cause extraordinary problems for your characters - unless you prefer playing clowns to playing heroes.

But hey, if that is the case, I can guarantee there are plenty of laughs to be had with the right group of friends!

Friday, November 25, 2016

D&D 5e: Advantage/Disadvantage converted to modifiers

Here is a quick comparison between advantage/disadvantage and flat bonuses. Lots of people have written about the subject, but since I couldn't find the exact table I was looking for (the last two columns in the table below), I thought you might find it useful.

Here is how it works: if you need to roll 5 or more in the d20 (column a), you have 80% chance of succeeding (column b), or about 96% if you have advantage, or 64% if you had disadvantage - which means that in this case ad/disad is equivalent to a 3.2 bonus or penalty (rounded to 3 in the last column).
d20 roll needed
d20 bonus/

As you can see, as long as you need to roll something between 8 and 14, the bonus/penalty of ad/disad is equivalent to +5/-5, or a bit less. But if you need a natural 20 to succeed, having advantage is only equivalent to a +1 bonus - which is not that bad really, since it doubles your chances of success. On the other hand, a Bless spell is often better than having advantage when you need a natural 19 or 20! 

The average bonus/penalty is 3.5 - which is equivalent to rolling a d6 and adding it to the d20 (notice I disregarded the "1" line, since there is no point in rolling if you need to roll 1 or more - and if you have a different solution, please explain your reasoning in the comments).

It is also worth remembering that this comparison doesn't take the benefits of a natural 20 (such as a critical hit, etc.) into account.

These numbers are not that hard to remember (but not that easy too). You may find it easier to square your chances of failure, when using advantage, or your chances of success, when using disadvantage. For example, you know you have 20% chance of rolling 17 or more - with disadvantage, this falls to 4% only (20% times 20%). If you have advantage, on the other hand, your chance of failure falls from 80% to 16%, which is 80% of 80% (source). Or just memorize the table above.

I'm not advocating replacing the advantage/disadvantage for something else*. But this knowledge can be useful in many ways: quickly calculating your chances when rolling two d20s, comparing advantage/disadvantage to various bonus and penalties (cover, bless, etc), translating advantage/disadvantage to other forms of D&D (with the OSR Rosetta Stone, for example), and so on.

More than anything, you can now roll ten d20 if ten goblins are attacking the party with advantage**, instead of rolling twenty times!

* In fact, I really like this mechanic. The coolest thing about it is that advantage is ALWAYS very relevant to you chances. Even at the extremes (when you need a natural 20, for example), remember that +1 bonuses will double your chances! Which falls within the realm of reasonable granularity to me.

** Example from the same source - thanks, Rob Conley! Also, every 19-20 should be a crit if you use this system instead of advantage.