Working after the steps of Homebrew Homunculus again, I was trying to make my own try at taking damage rolls from combat. One hit is one hit, so it takes one hit dice. Easy! Is fast, simple and requires almost no conversion. But of course, this started the design train: you change a little thing, and then you change another one to go with that, and end up having a whole different game.
I thought on making the fighter do multiple attacks instead of getting to hit bonuses. Even if the average damage per round was the same, there could be the chance that each round none of the attacks landed, or any number of them would. This way, there would be a kind of "variable damage" without any damage roll taking place!
But there is a number of how many d20s one can roll simultaneously in a confortable way. So I ended up doing what I had already done other times, and made it with d6. Only that, this time, I did the math.
This an orientative chart on the damage output of an attacking PC (where a 100% represents doing consistently 1 hit dice of damage per turn over time) depending on their class/level and his/her opponent AC.
This other table shows the % damage output of Fighter 1 (a just made level 1 fighter) versus enemies with various ACs (still not assigned what kind of AC do these numbers represent, so I described them as Base, fightey, soldier and tank). He rolls 1d6. Fighter "2" rolls 2d6 and Fighter "3" rolls 3d6. Each result equal or over the AC is a hit, and again, the chance of dealing consistently one hit every turn is represented as 100% damage.
If we look at fighter 1 alone, we see that AC 3 is slightly easier to hit than the "base" in d20. AC4 is a little worse than d20 leather (actually corresponds to wearing just a shield in the original), AC 5 being roughly equal to chain and AC 6 being an enchanted +1 plate and a shield.
Then it shows the chances of hitting the same enemies by fighter "2" and fighter "3". The brackets are there because we dont know yet at which level would a character get their second and third attacks.
As I see it, if we take the AC6 (Tank) to be roughly equivalent to Enchanted Plate + Shield, the chances to hit are pretty similar than if Fighter "2" was a 7th level fighter and Fighter "3" was a 10th. Well, this can be worked with. We can make it so the fighters gain other bonuses like weapon expertises, AC bonuses by using armor or extra HD until then, and the additional attacks are gained at those levels. But I'd lean towards granting them the attacks earlier, as otherwise the fighter hasnt any kind of "to hit" bonus until then.
But if we look at the lowest ACs, we see that the increments compared with their d20 counterparts are crazy: the chance to hit base AC is doubled, and the same could almost be said about the next higher one. AC5/chain stands a little better with just slight increments. This informs us that our new high level fighters are roughly equally capable vs higher armored foes, but are about double as capable vs unarmored foes or lowly armored mooks. This could be seen as a problem or as a boon. For one, I can see it fixing the problem in which high level fighters had to slay hordes of mooks one by one. Now they can just send an attack to three 1HD enemies at once with a great chance of killing them, without the aid of any cleave or "you can attack as many 1hd enemies as your level" houserule.
Greater ACs (AC7) can be attempted for certain monsters by using certain tricks:
* If you roll a 6, roll 1d6: on 4+ you deal 1 wound.
* If you roll a 6, the monster is at disadvantage for 1d6 turns (lower the AC until then)
* Certain weapon expertises might grant you situational bonuses. Aiming a bow for a turn for +1; Swords giving you AC bonus for a round on a failed roll, and a +1 bonus on the next round. Greatweapons treating rolls of 6 as if it was a 7. Etc.
You can always make AC6 monsters tougher by other means. For example, a giant might only be attacked after you dodge his attack first. If you are hit by him, you suffer the wound and cannot act for one turn. I kind of prefer to work out on this approach for two reasons: because is simpler, and because it invites me to be more creative with monster rules.
How does strength, magic swords, different weapons, etc factor into this? Well, this is the foundation. We will have to slowly figure out the rest around it, but that will be part of a new entry. For the sake of making reading this easier, the provisional codename and blog tag for this project will be d6 d&d.
On the other hand, working the saves is very straightforward. Here is how I would set them (taking the fighter saves as a guide) using 2d6 vs target number, or 1d6 roll under. I dont think I'd advance them more than that. A 100% chance of saving should never be reached, and there has to be room for other bonuses that might come from elsewhere.
(Notice the drop on the saving chance for first level characters. Today I had one guy rolling his 1 just before running into a pit trap with only one hit remaining. Yeah!)
What I like best from the X in 6 variant is that it can be used with advantage/disadvantage mechanics (roll 2 dice, take worst or best) when confronted with certain hazards or aided by certain boons, instead of using + or - modifiers. Hobbits and dwarves might use advantage, or just be a level ahead the other classes in the party.