I hate the shit out of games that use percentile dice mechanics and try to present a serious setting: CoC is one of the worst offenders in my book. The wiff factor results in absurd situations where a master locksmith fumbles a roll with a simple lock and the GM has to explain how he slipped on a banana peel or had an explosive fart and ended up bashing his brains in on the doorknob. Now for games that have an intrinsic dark comedy element like WFRP, percentile mechanics are brilliant because you WANT that kind of crap to happen now and then. But for games like CoC, it's crap. (Unless you are doing a comedy game, then... uh... more power to you, I guess.)

But one game that actually does a pretty good job incorporating percentile mechanics with a somewhat serious setting atmosphere is good old MERP. Yeah you can still completely blow a roll (I know there are games out there, like Trail of Cthulhu, that make success basically guaranteed... I don't enjoy that either!). But MERP has a whole range of outcomes between "success" and "failure": in fact, on a normal roll, you are much more likely to get a partial success than anything else... you get what you wanted to get, but not how you wanted it. You open the door, but cause noise that draws attention, or you break your last lockpick, or you take so much time that the cult is nearly done with their ritual by the time you get the door open. (If you don't know, in MERP you roll 1d100 plus your skill, so like 1d100+52, and compare it to a table to see the result... failure, partial success, success, critical success etc.)

 So tell me why it's a horrendous idea to rip off the MERP tables and shove them in Call of Cthulhu?

Quote from: Theros;1113666So tell me why it's a horrendous idea to rip off the MERP tables and shove them in Call of Cthulhu?

Many people claim that CoC is all about hopelessness and the PCs dying horribly, so you want mechanics that encourage failure.

More seriously, while I don't see anything wrong with your idea, I'm not sure I agree with your description of how the straight percentile mechanic works. For me it's a matter of when you call for a roll, and I generally don't call for rolls in routine situations. A "drive car" skill of 90% doesn't mean that you crash 1 out of every 10 times you get behind the wheel. It means that even in the middle of the night in a torrential rainstorm on a muddy unpaved road you still have a 90% chance of escaping whatever monster is chasing you instead of losing control and skidding off into a ditch.

Quote from: Dimitrios;1113668Many people claim that CoC is all about hopelessness and the PCs dying horribly, so you want mechanics that encourage failure.

More seriously, while I don't see anything wrong with your idea, I'm not sure I agree with your description of how the straight percentile mechanic works. For me it's a matter of when you call for a roll, and I generally don't call for rolls in routine situations. A "drive car" skill of 90% doesn't mean that you crash 1 out of every 10 times you get behind the wheel. It means that even in the middle of the night in a torrential rainstorm on a muddy unpaved road you still have a 90% chance of escaping whatever monster is chasing you instead of losing control and skidding off into a ditch.

That's fine, but it's still binary when you do eventually pick up the dice... pass/fail. You could make degrees of success (like rolling under a related attribute is a critical success), but it's harder to work in anything more complicated than that.

Quote from: Theros;1113666I hate the shit out of games that use percentile dice mechanics and try to present a serious setting: CoC is one of the worst offenders in my book. The wiff factor results in absurd situations where a master locksmith fumbles a roll with a simple lock and the GM has to explain how he slipped on a banana peel or had an explosive fart and ended up bashing his brains in on the doorknob....

I'm riding the whiff factor big and hard in the current 5e D&D game I'm playing in.

Wanna jump across 5 platforms suspended over a mist filled pit? Five separate rolls please...

It's to the point that I have started to factor it into what tasks I really want to try.

Quote from: Dimitrios;1113668Many people claim that CoC is all about hopelessness and the PCs dying horribly, so you want mechanics that encourage failure.

Ahh yes the 'Misery Tourism' mode of play espoused by a certain set.

My CoC game: Cultists are for the killing...

Quote from: Dimitrios;1113668More seriously, while I don't see anything wrong with your idea, I'm not sure I agree with your description of how the straight percentile mechanic works. For me it's a matter of when you call for a roll, and I generally don't call for rolls in routine situations. A "drive car" skill of 90% doesn't mean that you crash 1 out of every 10 times you get behind the wheel. It means that even in the middle of the night in a torrential rainstorm on a muddy unpaved road you still have a 90% chance of escaping whatever monster is chasing you instead of losing control and skidding off into a ditch.

Except in virtually all d100% systems I have seen, RAW: they start piling on the negative modifiers when it gets dark, and if it's really pouring down, and again if the road is slippery.

90% ?   Not so much...


I ran the quickstart scenario for the new Conan 2d20 game, and came away thinking that the basic 2d20 mechanic could just be the cure that ails if someone were to splice it in with a Mythras/Openquest system using the 2d20 for task and combat resolution instead of d100.

The basic 2d20 mechanic is rather neat, it was the rest of the game I found overly fiddly with damage dice mechanics and doom pool fiddly points put in to show just how clever the designers were.

Quote from: Jaeger;1113704Except in virtually all d100% systems I have seen, RAW: they start piling on the negative modifiers when it gets dark, and if it's really pouring down, and again if the road is slippery.

You're still not going to have to make a roll if you are just going to the library for research. It's when you try to do something tricky... like outrace the cultists during that rainstorm... that's when the dice come out, and bad weather conditions add to the difficulty. Otherwise it can be assumed you are a decent enough driver (given that 90%) that you will slow down a bit on wet roads and such.

Not seeing a problem.

You're going to want to find ICE's Ten Million Ways To Die for the firearm and martial arts tables.  Mostly it's an easy port but I'd give out SIZ + CON x 5 HP because the damage results are so much higher than CoC.

Quote from: Dimitrios;1113668Not seeing a problem.

Missing the context to which I replied.

Quote from: Dimitrios;1113668... I'm not sure I agree with your description of how the straight percentile mechanic works. For me it's a matter of when you call for a roll, and I generally don't call for rolls in routine situations. A "drive car" skill of 90% doesn't mean that you crash 1 out of every 10 times you get behind the wheel. It means that even in the middle of the night in a torrential rainstorm on a muddy unpaved road you still have a 90% chance of escaping whatever monster is chasing you instead of losing control and skidding off into a ditch.

See in Bold.

Quote from: Simlasa;1113710You're still not going to have to make a roll if you are just going to the library for research. It's when you try to do something tricky... like outrace the cultists during that rainstorm... that's when the dice come out, and bad weather conditions add to the difficulty. Otherwise it can be assumed you are a decent enough driver (given that 90%) that you will slow down a bit on wet roads and such. ....

RAW the game adds modifiers making the chance less than 90%.

I appreciate Dimitrios's sentiment, but most play CoC/BRP more or less RAW, and in a linear system like d100 games you get the swingy results the OP complains about. (and me.)

But BRP  is a popular system.

My view towards is heavily colored by my history with RPG's.

Other than b/X when I was really young, It was all diepool games; 1st edition SWd6 then Vampire then Shadowrun and riddle of steel. Even AW based games and my own d6 homebrew system starwars game.

Coming off of years of playing games with some kind of die curve, I find I notice the swingy nature of d20  and d100 based games more than people who play them routinely.

Quote from: Jaeger;1113722Missing the context to which I replied.

How so?
You complain your chances are too low... it's explained to you that those chances are ONLY for when you're doing risky shit... I support the idea that risky shit piles up and makes risky shit riskier.
You're still not rolling for any everyday use of the skill.
Seems sensible to me, and fits the game as I want to play it.
If I want to play James Bond (with the appropriately ridiculous car stunts) then I'd pick a different system.

The current edition has a couple of rules that let you avoid the "swinginess" of the D100 system. It doesn't fix the underlying problem, but it does mitigate it for "vital" rolls. There's the push rule (for dangerous tests, you can re-roll but if you fail a bad thing will definitely happen) or you can burn points of luck (permanently) reduce the die roll so that you succeed. I prefer the first, but both are available to the Keeper should they want them.
But no, it doesn't actually fix the underlying issues (and there are more than the one you highlighted) with the D100 system. Still, it works for me. YCMV.

I run WFRP 1e and I used to run CoC for decades. I totally understand Theros' concern, but in actual play it hasn't been an issue. He's right that the swingy randomness adds to the Warhammer madness where its fine when you behead a demon with a critical, but then walk blindly right past the macguffin because you blew your search check. It's a bit less useful for CoC.

For me, how you fail or succeed in a D100 game is what matters. If you have Library Use 40%, I'm not going to cause a disaster if you roll 60%, but instead you will need to devote more time or learn you need to go elsewhere for your answers. But if you roll over double your skill, then you blundered and that's okay.

BTW Theros, if you enjoy horror RPGs, check out Silent Legions by Sine Nomine. It's OSR and even if you don't use the system, the resources in the book for horror campaigns are amazing.

Quote from: David Johansen;1113712You're going to want to find ICE's Ten Million Ways To Die for the firearm and martial arts tables.  Mostly it's an easy port but I'd give out SIZ + CON x 5 HP because the damage results are so much higher than CoC.

Good suggestion, thanks. To be honest, since CoC has such a specific feel to it in terms of firearms and lethality (and how that scales with supernatural monsters), I might just figure out a way to keep using CoC rules for combat and just use MERP tables for investigative and non-combat rolls. MERP (and presumably Rolemaster) is really about showcasing combat talent... the more skilled you are, the more deadly you are. That is still true with CoC but it is more muted (and unless you are running Pulp Cthulhu, it probably is less on-message with the atmosphere of CoC to allow investigators to become combat machines).

Quote from: Spinachcat;1113741I run WFRP 1e and I used to run CoC for decades. I totally understand Theros' concern, but in actual play it hasn't been an issue. He's right that the swingy randomness adds to the Warhammer madness where its fine when you behead a demon with a critical, but then walk blindly right past the macguffin because you blew your search check. It's a bit less useful for CoC.

For me, how you fail or succeed in a D100 game is what matters. If you have Library Use 40%, I'm not going to cause a disaster if you roll 60%, but instead you will need to devote more time or learn you need to go elsewhere for your answers. But if you roll over double your skill, then you blundered and that's okay.

BTW Theros, if you enjoy horror RPGs, check out Silent Legions by Sine Nomine. It's OSR and even if you don't use the system, the resources in the book for horror campaigns are amazing.

Thanks yeah, I've been meaning to check Silent Legions out.

Quote from: spon;1113739The current edition has a couple of rules that let you avoid the "swinginess" of the D100 system. It doesn't fix the underlying problem, but it does mitigate it for "vital" rolls. There's the push rule (for dangerous tests, you can re-roll but if you fail a bad thing will definitely happen) or you can burn points of luck (permanently) reduce the die roll so that you succeed. I prefer the first, but both are available to the Keeper should they want them.
But no, it doesn't actually fix the underlying issues (and there are more than the one you highlighted) with the D100 system. Still, it works for me. YCMV.

Yeah, it adds a bell curve when you throw in advantage dice etc. It's still a binary success/fail system though, which is why I am thinking  about systems that emphasize "partial success."

Just steal degrees of success from WFRP 2nd ed (every 10 by which you succeed or fail by is 1 degree). Leaves a lot of room up for the GM/Players to determine what it really means but if you are that dead set against binary results then that should work for you.

Quote from: lordmalachdrim;1113753Just steal degrees of success from WFRP 2nd ed (every 10 by which you succeed or fail by is 1 degree). Leaves a lot of room up for the GM/Players to determine what it really means but if you are that dead set against binary results then that should work for you.

That would work too!

Quote from: Theros;1113750it probably is less on-message with the atmosphere of CoC to allow investigators to become combat machines).

Actually I was thinking about this and what I might do is take out combat skills entirely, so that your chance to hit is fixed and cannot improve. For example, all firearms could be fixed at DEX x 5 for military, DEX x 4 for civilian careers that train in weapons (police, hunters, mobsters etc.) and DEX x 3 for everyone else. Melee would be STR x 5 for men and STR x 4 for women (representing physical differences, but also cultural differences in the 1920's). Would that break the game? The point is to make the player-characters focus less on violent skill improvement and more on other areas (since Cthulhu Mythos characters are investigators in the tradition of Sherlock Holmes, not Batman).

The key to the BRP-system (and most other systems) is to define your successes and failures. A success means you progress in some meaningful way, a failure means you don't - how depends on the situation. To go with your example of the master locksmith and the keyless lock. The lock is going to lose every single time, the variable is how long it is able to hold out.