Making a d% based skill based system - sort of a cross between Runequest and d20

[Zireael]

This is a project to create an original RPG system, which could be used as tabletop or as a computer game.

The game is supposed to have a ‘gritty’ feel and combat should be dangerous.

What I liked in d20:
• roll over - I find ‘roll high to succeed’ more intuitive than ‘roll under’
◇ however roll over is bad for d100, as it measures chance to fail instead of ‘chance to succeed’
• races
• challenge rating - an easy way to determine if the monster is stronger or weaker than you

What I liked in RQ:
• use of a d100 - I believe a d100 will be easier to convert to percentages to present to the player
• skills
• hit location/body parts
• advance skills by using them


This is the first draft of the system, feel free to poke any holes in it and ask questions and drop ideas.

https://www.dropbox.com/s/9ayq2xmnj2...n-ctd.pdf?dl=0

What's to come:
- I plan to have two hp tracks (sorta like d20's variant vitality and wounds or like Darklands had strength/endurance
- Describe how light and darkness, darkvision all work
- Ranged weapons need ranges, item lists are incomplete, most prices need updating

Things I have problems figuring out:
- For the computer game (and for a tabletop DM), I need a way of quickly adjudging how dangerous a given NPC/monster is - what "challenge rating" is in d20. Any ideas? This does not need to be a "level" per se as I like the skill-based aspect of this, but might be - 5% total increase equalling a level? just spitballing...
- Determining how a combat round looks. I'm more and more partial to Action Points, but rather than turn-based points, I am thinking of turnless system, where numbers are just points on a timeline... I take an action at point 0 which takes 10 units, I can take an action again at point 11, an enemy takes an action at point 1 which takes 20 units, it can act at point 22... that sort of thing.

Any ideas/help?

[Bruno Carvalho]

You can take a page from SeeD, which uses a initiative system akin to what you want to do:

http://storagebin.wikispaces.com/SeeD

[Zireael]

Thanks! I already have the entire code for the turnless action system for the computer game, but the link will definitely help me describe this for the tabletop version.

Any ideas concerning the CR equivalent (a measure of power)?

[Zireael]

Another part I'm having trouble with is hp - I'd like them to be tied to both Con and the starting class, and for the player to be able to increase them a bit in the course of adventuring. Less so than in d20, or at least taking MUCH longer to reach results in the 100s. Any ideas how to achieve this? I could make them a special skill that only advances when taking damage?

As for combat power, I could take the average of all combat skills.

How do you like the draft skills list?

[Bruno Carvalho]

To be true, If you want to keep the "gritty" idea, since your stats don't scale with level and damage don't scale with skills, just use fixed HP. High-level characters live longer because they have bigger dodge values, not because they have huge HP ratings.

[Zireael]

your stats don't scale with level and damage don't scale with skills,

Stats do scale with experience - you can sacrifice a number of improvement rolls normally made to improve your skills through use to increase stats, within reason.

To be true, If you want to keep the "gritty" idea, [...] just use fixed HP. High-level characters live longer because they have bigger dodge values, not because they have huge HP ratings.

As I mentioned in OP, I was thinking of two hp tracks. One could be fixed (wounds) and the other (endurance/vitality/hp) could be the one that increases a bit, maybe with the combat level? Having both fixed would make progress too invisible from the player's point of view, I think. Going from 'I can withstand one hit with a sword, maybe' to 'I can withstand one sure hit AND a nick', that sort of thing, would be better IMHO.

[Zireael]

I did a couple of sample characters with a piece of paper. For a starting fighter and stats between 16 and 8, the defense stats are between 30% and 50%. The weapon skills are between 40% and 55%. The other skills, for which you currently have 75 points to split, range between 20 and 30%, and this after adding +10% to all fighter class skills.

Isn't it a bit too low? d20's DC 10 is roughly 55%, after all.

[Zireael]

So, any ideas about hp and/or the starting percentages (two last posts)?

[Grod_The_Giant]

I did a couple of sample characters with a piece of paper. For a starting fighter and stats between 16 and 8, the defense stats are between 30% and 50%. The weapon skills are between 40% and 55%. The other skills, for which you currently have 75 points to split, range between 20 and 30%, and this after adding +10% to all fighter class skills.

Isn't it a bit too low? d20's DC 10 is roughly 55%, after all.

Yes, that's very low. I like a success rate of somewhere between 2/3 and 3/4, generally speaking-- high enough that you can reasonably expect to succeed at common tasks, but low enough that failures will still happen.

As for health... I'm a fan of plot armor/serious injury splits, like in Fate. You have a pool of virtual health that recovers very quickly after a fight, meaning you don't need a "healer" character to waste resources patching you up after every skirmish, but when it runs out you take a serious hit with a long-lasting penalty.

[Zireael]

Yes, that's very low. I like a success rate of somewhere between 2/3 and 3/4, generally speaking-- high enough that you can reasonably expect to succeed at common tasks, but low enough that failures will still happen.

As for health... I'm a fan of plot armor/serious injury splits, like in Fate. You have a pool of virtual health that recovers very quickly after a fight, meaning you don't need a "healer" character to waste resources patching you up after every skirmish, but when it runs out you take a serious hit with a long-lasting penalty.

Well, giving starting characters success rates in 2/3 or higher means skill values of 66% or more, where is room for advancement in that? What are the success rates for starting characters in Runequest? I'm not really sure... but I don't think they're >66%...

As for health, that's a really nice solution. Sort of what I'm aiming for here. Virtual health that you recover fast and wounds that have nasty effects.

[Zireael]

I am sticking to having two hp tracks. I named the fast-recovering one "endurance" and the slow-recovering one "health".

Reducing a limb to half health incures penalties to those skills that use the limb. I was thinking of the penalty being 10% (equivalent to a -2 penalty on a d20 test). I was thinking of converting http://paizo.com/pathfinderRPG/prd/u...lledShots.html to d% somehow. Reducing a limb to 0 health renders it useless.

In the current draft, you recover 4xCon/5 endurance but only one health point per 8 hr rest. I'm unsure on how to split the recovered points over the limbs. Well, endurance is fairly easy, health is a bigger problem.

[Grod_The_Giant]

Well, giving starting characters success rates in 2/3 or higher means skill values of 66% or more, where is room for advancement in that? What are the success rates for starting characters in Runequest? I'm not really sure... but I don't think they're >66%...

Sorry, I thought I'd replied to this days ago. In a nutshell, then... the goal of advancement is less "I can do the same things more reliably" than "I can attempt new and more exciting things." Roll-high systems kind of do this automatically, but even here you can use special abilities to add functionality, rather than raw probability. Say that you have the listed... what was it, four levels of skill? So you have something like:

Jump

• Novice: You can jump (Str) feet with a running start, or half that as a standing leap. Half this distance for vertical leaps.
• Apprentice: Add 5ft to your jump distance, and you only need a 10ft running start
• Veteran: You no longer need a running start, and you can take your standard action mid-leap.
• Seasoned: You can jump once each round as a swift action.
• Master: Double all jumping distances.

Each level makes you noticably better at jumping around like a mustachioed plumber, but in ways that don't interact at all with the probabilities. (Note that you should probably use more precise language than I am here; I'm being lazy)

Also note that you can also advance from, say, 60% to 80% without really breaking probability too far in any direction. So you could have, say, a base rate of 40%+ability for untrained skills and 50%+ability+level for trained skills.

I am sticking to having two hp tracks. I named the fast-recovering one "endurance" and the slow-recovering one "health".

Reducing a limb to half health incures penalties to those skills that use the limb. I was thinking of the penalty being 10% (equivalent to a -2 penalty on a d20 test). I was thinking of converting http://paizo.com/pathfinderRPG/prd/u...lledShots.html to d% somehow. Reducing a limb to 0 health renders it useless.

In the current draft, you recover 4xCon/5 endurance but only one health point per 8 hr rest. I'm unsure on how to split the recovered points over the limbs. Well, endurance is fairly easy, health is a bigger problem.

So... going from general health pools to tracking individual limbs is an instant jump in complexity. As with any such decision, you should step back and think about why. What's the big thing you're looking to gain? Is it going to add an interesting bit to the game, or is every shot going to be aimed at the head now? Could you replace it with something simpler-- say, "when you run out of health, roll 1d6 to find where the blow landed; that limb/head/chest is now crippled, with X penalty."

Also, what's the in-game split between Endurance and Health? What sort of tone are you looking to emphasize with that rule, and that manifestation of it?

[Zireael]

So... going from general health pools to tracking individual limbs is an instant jump in complexity. As with any such decision, you should step back and think about why. What's the big thing you're looking to gain? Is it going to add an interesting bit to the game, or is every shot going to be aimed at the head now? Could you replace it with something simpler-- say, "when you run out of health, roll 1d6 to find where the blow landed; that limb/head/chest is now crippled, with X penalty."

Also, what's the in-game split between Endurance and Health? What sort of tone are you looking to emphasize with that rule, and that manifestation of it?

I want the combat to be dangerous. Having limbs have different health and protection allows me to make more interesting NPCs as well as more item variety (do you buy a breastplate piece or a plate armor greaves? seeing as you have limited funds). Also I'm fond of the piecemeal armor trope, this is what happened most often in reality - mercenaries had a bit of this a bit of that, none of those 'knights in full chainmail/full plate' depending on period.

The endurance/health split allows me to have weapon damage that is noticeable (1d8 or something instead of 1d2) without risking immediate death from a single blow. Moreover, endurance can have one definition and health the other. It is better than having a single health pool which is then difficult to explain (how many discussions were had whether d20's hp is luck, health, vitality or something even else? and that all hits until some treshold are 'glancing blows' or 'they don't even bleed you' to explain why you can be hit 10 times with a sword at higher levels and not die)

[Zireael]

Casting *Resurrection*, as I'm the original poster.

Also note that you can also advance from, say, 60% to 80% without really breaking probability too far in any direction. So you could have, say, a base rate of 40%+ability for untrained skills and 50%+ability+level for trained skills.

That's a very good point I failed to notice originally.