Nothing is created from a void, there is inspiration everywhere. There have been plenty of examples on the internet where game designers have failed to acknowledge the sources inspiring their work. I'd rather look at those inspirations, show people where ideas came from, perhaps to learn from other people's insight, maybe to show other game designers how they can draw similar inspiration, or maybe just because it's polite and the right thing to do.
I can think of four distinct sources of inspiration that have blended together, there are probably a whole heap more, but these are the main ones.
Firstly, I'm thinking of the combat system in Warhammer Fantasy Battle (or more specifically "Mordheim"). In this system, a combatant rolls a number of dice equal to their "attack" score, if fighting an opponent with equal skill ("Weapon Score"), a roll of 4 scores a "hit". Each successful hit sees an aggressor compare their "Strength" to the defender's "Toughness" then roll another die, if the strength and toughness are roughly equal, a roll of 4 will translate that hit into damage. One damage is all it takes to neutralise most characters (and take them out of the game), some more powerful characters and heroes will have extra hit points.
It's a bit convoluted, but it lays the groundwork for where I'm headed with the conflict system...and it certainly uses the "4" as a benchmark for success. This system makes things easier or more difficult by cross referencing numbers for the attacker and defender, thus giving a target number for a d6 to match. I'm looking at changing die sizes, and modifying the number of successes required to achieve tasks, but there are certain elements that remain intact.
Secondly, the free RPG "Warrior, Rogue and Mage" by Michael Wolf (which can be found at http://www.stargazergames.eu/games/warrior-rogue-mage/). One of the interesting things about this game is that it doesn't give the characters attributes in the traditional sense, instead it allows players to assign levels in the occupations of Warrior, Rogue, or Mage, then the player determines their chances of success in various actions by rolling a die and adding the appropriate occupation level. It strips back so many of the stereotypes in gaming to the essentials, even more than many of the "microlite" games I've read over the years. In WR&M, a single die is rolled, and the occupation level is added, it's a simple pass/fail system...in "System 4" a number of dice will be rolled, each capable of gaining successes (as well as "advantages" and "disadvantages"), thus giving a more dynamic range of outcomes. But there is certainly a link of inspiration between the two systems.
"System 4" won't be reducing things quite to this level, I'm looking at 6 basic actions (rather than WR&M's 3 types)... i'll be working with Combat, Diplomacy, Faith, Knowledge, Magic, and Trickery. Each with it's own specialist occupation, and a variety of occupations that straddle two attributes/categories.
Thirdly, Cadwallon, the short lived RPG from Rackham (before it imploded). I've talked about Cadwallon before on the blog, because it had a few really interesting ideas in it. One of the ones that really caught my imagination was the idea that a character's frame of mind might change the range of things they are able to do. When a character is angry, they can't think straight and do delicate things. Each frame of mind forms a "stance" (and these stances correspond to the attributes), and each stance/attribute has a certain range of skills that may only be attempted when the character has a relevant frame of mind.
Since "System 4" uses types of action as the attributes, characters will basically declare their intended turn motivation at the start of the round (rather than Cadwallon's declaration of emotion). For example, a character going for damage will declare that they are using "combat" for the round, while a character trying to decrypt ancient runes would declare "knowledge". The corresponding dice for the attribute are rolled, and any 4s count as successes. Characters would also have abilities that might grant automatic successes or have other effects on the round's outcome. I'm considering allowing characters to perform actions not covered by their declared stance, but this might require the expenditure of extra successes to get lesser things done (if in combat stance, it might cost two successes to do something normally requiring knowledge).
Fourthly, the die mechanism in Star Wars: Edge of Empire, where multiple dice are rolled, and each is able to add successes, failures, advantages and disadvantages to the final resolution. I've gone into a bit of detail on this previously, and it's basically where the whole thing started.
Finally, I remember reading about the origins of hit dice in D&D. Going back to the original "Chainmail" rule set, where a character's hit dice were basically a measure of their power, resilience against negative effects, and even their combat skill...all in one number. In D&D there is still a remnant of this in a cleric's ability to turn undead of different hit die levels, but in most other parts of the game it has faded into insignificance.
"System 4" is pulling this idea back into prominence, but the various dice come into play for different types of action. Dice in "Diplomacy" count for a characters ability to persuade others, but also show a character's resistance to the diplomatic manoeuvring of others.
Lots of ideas, pulled together into a coherent system (hopefully).
Now I'm just thinking of the specific mechanisms that will make the game work in the ways I've envisioned. More thoughts to come.