One thing I'm really tired of in RPGs is the constant bookkeeping of everything from initiative order, ammo, money, castings per day, et al. So I want my system to keep bookkeeping to a minimum.
Initiative or Turn Order
Shadow of the Demon Lord has a genius initiative system. There are fast turns and slow turns. During a fast turn, you can only move or do something, while in a slow turn you can do both. Players always get the chance to do their fast turns first, then the antagonists choose to do a fast or slow turn, and so on.
Now, an even more streamlined version of this could be to give antagonists a set turn, the equivalent of a slow turn above, and they go first. However, a player can then choose, I love systems that let players choose their own doom, to take a fast turn before the antagonists get their turn. Those who don't must wait till after the antagonists are done. The trade-off here is that you choose to do only a move OR an action if you go fast.
Wealth, Ammo, and Other Bookkeeping needs
There's been a few interesting systems for removing the need to bookkeep stuff.
My favorite system for keeping track of ammo is the ammo die. This means that when you've filled up, you have a d20 ammo die which you roll whenever you shoot your bow. If the d20 rolls a 1 or 2, you reduce this die to a d12, then a d10, d8, you get the idea.
Another system I have seen over the years is the Wealth or Credit Rating system. Your Wealth is a skill, characteristic, or similar and whenever you need to spend money you roll against it. Success means you can afford it, failure means you can't. Add a fail-forward condition to this and suddenly bartering starts to become a lot more interesting.
I want to use a single system for all such bookkeeping needs though, so the players don't have to keep track of several types of dice for one type of bookkeeping while tracking skills for another. So I'm thinking all such things will use a value, not unlike a skill, but more like a characteristic since it will be prone to fluctuations.
Ammo could be handled through the attack roll. So with a complicated success, the player could choose to only have 1 ammo left to turn it into a complete success. Or something similar.
Or if you need to buy something, you roll a number of dice equal to your Wealth characteristic. Any complicated successes would let the player choose to reduce their Wealth by 1 to turn it into a complete success, allowing them to afford whatever they wanted to buy. Or they could choose some story element instead. Lots of potentials here.
So while I'm not completely decided yet, it looks like I might tie all ammo, money, et al, bookkeeping to rolls.
I'm thinking that Wealth can be a characteristic that fluctuates. So most everyone starts with Wealth 1, which gives them 1 die to roll when they need to buy stuff. Background or in-game events can raise or lower this number. So while you create your character and you roll on your life path you get a Wealthy result or something, raising your starting Wealth by 2. You would start with Wealth 3. Giving you 3d6 to roll when buying stuff.
I'm also thinking stuff should require a number of successes based on their availability. Availability is derived from its rarity and current market. So buying a common or uncommon item in a city is 1 success. A complicated success could make the item shoddy or something, while critical successes (successes beyond the needed 1) could make it better, up to masterwork. A rare item would require two successes and an exotic one would require three successes. A rural town would perhaps require another success for rare and exotic, while a tiny village might not even have the better stuff.
Anyway, complicated successes could then be chosen to make sure they get an item. And some complications could make the item of worse quality, or maybe it was stolen and buying it will put a target on your back, etc. I'm also thinking that you can "spend" Wealth to assure you get something. So if you lower your Wealth by 1, you could add successes to your roll, or maybe even forgo the roll completely?
Needs to be playtested!
It doesn't make sense to have a characteristic for ammo IMHO. So it would instead be a property attached to a weapon using ammo, for example, a Tommy-gun. I want ammo-tracking to be simple without removing the fun though, so maybe ammo also has a value. Let's say an ammo value of 1 equals exactly that, you have a single shot left. But 2 is one step up, so for a Tommy-gun, this would mean a 20-shot box magazine. 3 would be a 30-shot box magazine, 4 would be a 50-shot drum, while 5 is a 100-shot drum. If this was a flint-lock rifle instead, 2 would perhaps be 5 shots, 3 would be 10 shots, 4 would be 20 shots, while 5 would be 30 shots.
This gives us an ammo value of 0-5, 0 being no ammo ofc, 1 being a single shot left, while 2-5 would be different based on the weapon.
Now, to spend this ammo I'm thinking that you just roll attack as normal. Let's say shooting uses Agility and you have an Agility of 2. And maybe you have a talent giving you a +2 on Submachine guns or something. So you roll 4d6, but you only get a single 6. Your target has an Agility of 2 too, so you needed 2 successes to hit them (not sure if this is how I end up doing combat, so this is just a suggestion). But you also rolled two complicated successes, so you could choose to reduce the weapon's ammo value to turn one of those into a success, making it a hit anyway! Maybe a failed roll (still need to make 1-3 more fail forward) reduces ammo automagically, no matter if you succeeded or not. Need to think more about that one.
Well, that's it for now on bookkeeping in the Mythos Engine. I have decided to join this year's NaGaDeMon to focus on developing this Mythos Engine further. So hopefully I will have a playtest ready during the coming month!
I have also joined the Story Collective's Write Your First Adventure course just to push myself into publishing an adventure for Call of Cthulhu and learn something in the process. So that is also happening this month.