Hello,

I've been thinking about RPG game mechanics and I wanted to share one in particular that I think is new and interesting. Well, new to me at least: I reviewed about 30 different systems[1] and I didn't see anything like it. That said, I expect/hope someone will correct my ignorance on its novelty ;-)

The basic idea:
The actual game mechanic is an action resolution mechanic and I've given it the (ungainly) name: 5dx. Here is how it works:
  1) State an action and assign a difficulty number based on game context, GM's mood, etc.
  2) Roll 5 like dice (I prefer d20's) and count up the dice that rolled equal to or higher than the difficulty number.
  3) Spend those 'success' dice towards effects based on the stated action.

An example:
  1) A thief attempts to pick a well crafted lock (Difficulty: 14+).
  2) The thief rolls 5d20 and gets: 2,7,13,14,16 for a total of 2 successful dice and 3 failure dice.
  3) Using the two successes, the thief hears a click as the first of three tumblers falls into place. The lock is not yet picked but the thief made progress.

Thoughts:

• The primary advantage of this system is that it lets players know the degree of their success (or failure) on a scale from 0 to 5. In contrast, most action resolution mechanics provide just a pass/fail result. IMO, this is too simplistic for most events in role playing games. I could go on and on about this but let me just say that just giving a yes/no response to whether a player finds a secret door, bluffs the guards or hangs onto a falling rope bridge reduces the potential for telling a story.

• Another bonus is that this is a quick mechanic in that there is no need to add the results of the 5 dice together. Actually, one of my friends who tried the system think that this is the pimary advantage :-)

• I found that one of the surprising side effects of this system is that it makes it easy to make rules for all kinds of tasks to be solved. Many events that are traditionally skimmed over so the party can enter their next combat encounter can now become dramatic challenges in their own right. In the lock picking example above, the lock has three tumblers that must be carefully worked into the open position but without going too far. This translates into the following rule: each turn that someone tries to pick the lock, their first success must be spent on not jamming the lock and the remaining successes are then spent on opening the tumblers (1 success per tumbler). I don't know about anyone else who played D&D but that is much more interesting to me than the usual percentile roll and pass/fail result. Below is a table of the results each turn someone attempts to pick the lock:

[table]
[tr][td]Success[/td][td]Result[/td][/tr]
[tr][td]0[/td][td]The lock is jammed shut and the lockpick used is broken.[/td][/tr]
[tr][td]1[/td][td]No progress is made.[/td][/tr]
[tr][td]2[/td][td]One tumbler is opened.[/td][/tr]
[tr][td]3[/td][td]Two tumblers are opened.[/td][/tr]
[tr][td]4,5[/td][td]All tumbers are opened.[/td][/tr]
[/table]

In a nutshell, the 5dx mechanic is a simple action resolution mechanic that describes how well an action was performed and that I think can be useful in many RPG's. I'm curious what game designers on this forum think about it.

[1] I looked at a lot of systems listed here: http://www.flick.com/~cdr/rpg/links.html

Couldn't you simply use just one die to get the desired result?  Example: the difficulty is 10.  The thief rolls 12, and gets two successes (success variance of +2).

You can also have a single die for success/failure and another for degree of success/failure. It's not mathematically the same though.

At any if you like to throw a bunch of dice around, this mechanic can fulfill that need admirably, no doubt ;)

Handling time rises with multi-die mechanics, and particularly with any mechanic that results in only partial success after a round of rolling.

Technically you could roll a number of rounds "whiffing" before finally getting the job done. Do you really need to roll 20d20 over the course of four rounds in order to determine that you picked a lock? Is there some narrative tied to the dice? Some tension that can be produced?

Well, new to me at least: I reviewed about 30 different systems[1] and I didn't see anything like it. That said, I expect/hope someone will correct my ignorance on its novelty ;-)

[Crossposted with Certified]

This is a basic dice pool system, similar to what's used in World of Darkness (Vampire, Werewolf, etc.). In older versions of the game, the GM (Storyteller) sets a difficulty number. In the new version of the game, the difficulty is always the same (8, I think) and certain tasks require more than one "success" (die of 8+), similar to your lockpicking example.

Be careful here. You're basically making GMs set two numbers: a target number for success and a number of successes required. This leads to fiddly situations where the GM is basically just making up numbers to get the result she wanted from the get-go.

"Uh, difficulty is 9!"
"I get... two successes!"
"Uh, but you needed three, so sorry."

Explicitly requiring the GM to make all of this plain before the dice hit the table can mitigate these problems to some degree. It's still two target numbers where you need only one, however.

Other dice pool systems to consider: Sorcerer (by Adept Press) uses pools of dice (often d10s) and counts the number of dice with the highest face. So if  you roll 7d10 and get 1 4 6 6 7 8 8, then you have two 8's. There is no difficulty number to compare against. You are always rolling against someone else's roll. So if I roll and get one 9, I beat your two 8's, but your two 8's would beat me if my highest was one 7 or even one 8.

Dice pool vs. target number systems often require you to bolt on special rules for when two or more characters oppose each other. Why not ditch the target numbers and just go dice pool vs. dice pool to begin with? It's not hard to create rules for creating dice pools for "characterless" situations that come up.

Hey, metagov,

A thought inspired by Adam's post: maybe you could create "sets" of difficulty? The GM tells you the difficulty: simple, challenging, really hard, or impossible. You pick a number of successes to get, and they correspond to a target number, or the other way around. The more successes you need, the lower the target number.
Such a system could be very fiddly in design, but not so much in practice - you could just sit and think for a moment about which option, and then try your luck. Depending on how character skill affects dice rolls, point bonuses vs. automatic successes could be an interesting trade-off.

And by the way, is there a real-person-style name you might prefer besides metagov? We like to keep it informal around here ^_^
Anyway, I think your idea sounds neat - you can gauge your level of success (or lack thereof) in a way that kind of turns the dice-pool on its head: you always roll the same number of dice, so the range you're working with is always the same.
It might make sense to have a setting, then, where character skill is limited, or doesn't change much, or isn't a factor at all - maybe everyday people in unusual situations, that kind of thing?

Where would you like to go with this? When folks come here with a "generic" mechanic in mind, i.e. one with no setting or "color" attached to it, it seems to me that's generally because there is a specific genre or setting style that they already have in mind - for example, many people post their combat mechanic ideas with the implicit assumption they'll be creating a fantasy adventure game. What are you envisioning?

As for your lock-picking example, I have a question: if you don't open all the tumblers in one go, what happens next? Is there something negative, or at least complicating, that occurs while you're trying again? Are the other tumblers beyond your abilities? Does partial success here mean that you'd be better at smashing the door open, since you "loosened it a bit"?
I'm intrigued by what could be a highly literal correlation between # of successes rolled and # of objectives achieved - do you see yourself using this sort of theme a lot? Could you give an example of combat, using this system? Any "bells and whistles" you'd want to put on it?

- Zac

@ Ar Kayon, Mathew E. Reuther:
Yes, you can certainly gauge degree of success by rolling a single extra die or by the difference between the actual roll and the target number. But the problem then is that huge successes/failures are just as likely as minor successes/failures and I want a system where the extreme degrees are exceptional events.

I'm not sure how useful this is but, when I was messing around with this idea, I came up with a spreadsheet[sup]1[/sup] and some graphs which show the odds of rolling successes given different target numbers on 1d20 and 5d20. What it shows is that 0 and 5 successes are always possible but generally unlikely to occur which is what I wanted.

Jonathan

[sup]1[/sup] google spreadsheet of odds: http://bit.ly/azXowF

@ Certified, Adam Dray
Thanks for mentioning the Storyteller/World of Darkness system. I'll look at that system (and dice pools) when I get a chance.

I agree that the extra task of choosing the number of successes in addition to a target number is potentially troublesome. In situations that really are simple yes/no events I'd have a convention that 3+ successes is equal to 'yes'. In all other situations, success and failure mechanics have to be described. E.g., picking locks, leaping pits, throwing horseshoes or hand grenades all get their own definitions of what success and failure means.

Also, one of the things really I want to avoid if at all possible is adding a variable number of dice to be rolled. This is tempting but it adds a third variable to the mechanic (target #, success #, dice #) which adds a lot of complexity. Plus, personally speaking, I'm trying to avoid rolling an arbitrary large handful of dice. (yes, yes, I'm lazy :-)

-Jonathan

@Abkajud,

Thanks for the sets of difficulty idea... I have to think about that one!

My real name is Jonathan Claggett (and my Cloak of Anonymity +1 was so warm...) feel free to call me by that handle.

Regarding where I want to go with this; sadly it's going nowhere at the moment :-( I came up with this about a year ago but I've had no time to spend the needed hours of work to build full game around the system. In fact, that's why I posted it in this forum in hopes that someone with more energy and creativity can make a really cool RPG that I can then play using it :-D.

I will say that I was targeting a generic dungeon crawl setting last year and I wanted to have a fast paced, rules light experience. Actually, I was trying to build a dungeon crawl game that had more depth in puzzle solving and other non-combat situations. I think the most exciting thing about trying to model quality of success is that non-combat tasks can finally get some fun game mechanics. In my experience, combat usually gets the lion's share of an RPG's rule budget and the rest of the game world tends to be anemic as a result.

Here is my favorite example of this: secret doors. In all the fantasy/mystery/thriller novels I've read, finding and opening secret doors is always a major source of drama and tension in the book and yet not so much in your average dungeon crawls. Just compare Gandalf trying to open the gates of Moria to the last time your party was awkwardly re-rolling d20's at the conspicuous dead end of a hallway. So, what I'd like to do for my (unlikely to be finished) game is to have secret doors be complex encounters in which it takes several successes to find the existence of a door and several more successes to find right the trigger to open the door.

Jonathan

So you want a tight bell-curve.  Ok, got it.

metagov wrote:
Here is my favorite example of this: secret doors. In all the fantasy/mystery/thriller novels I've read, finding and opening secret doors is always a major source of drama and tension in the book and yet not so much in your average dungeon crawls. Just compare Gandalf trying to open the gates of Moria to the last time your party was awkwardly re-rolling d20's at the conspicuous dead end of a hallway. So, what I'd like to do for my (unlikely to be finished) game is to have secret doors be complex encounters in which it takes several successes to find the existence of a door and several more successes to find right the trigger to open the door.

Mathew wrote:

metagov wrote:
Here is my favorite example of this: secret doors. In all the fantasy/mystery/thriller novels I've read, finding and opening secret doors is always a major source of drama and tension in the book and yet not so much in your average dungeon crawls. Just compare Gandalf trying to open the gates of Moria to the last time your party was awkwardly re-rolling d20's at the conspicuous dead end of a hallway. So, what I'd like to do for my (unlikely to be finished) game is to have secret doors be complex encounters in which it takes several successes to find the existence of a door and several more successes to find right the trigger to open the door.

Why is it exciting to take multiple rounds finding a secret door with dice?

So would you envision this mechanic as a "sub-feature" of the system, to be used like "Skill Challenges" in D&D 4e, or would it be the primary method of resolving all tasks?

Hi,

3) Spend those 'success' dice towards effects based on the stated action.

As usual, the GM is free to move the story along

metagov wrote:
Regarding where I want to go with this; sadly it's going nowhere at the moment :-( I came up with this about a year ago but I've had no time to spend the needed hours of work to build full game around the system. In fact, that's why I posted it in this forum in hopes that someone with more energy and creativity can make a really cool RPG that I can then play using it :-D.