Codex Martialis

I'm probably out of my mind even considering this, since my coding skills are ridiculously poor, but I'm considering working out a mod for the Codex Martialis add-on for d20. I have some questions about proceeding that I hope some folks here can help me with.

First off I would like to be able to continue using the existing updates for the D&D 3.5 datasets, but I do need to make some significant modifications to a few things, including capping HP at 2x CON, creating a new set of Martial Feats (completely separate from standard Feats and given out with every point of BAB), modifying the weapons and armor tables as well as figuring out new traits with those new figures. With that level of customization required, is it even possible to work with the standard and updatable d20 dataset and adding CM in as an add-on at all? I'm thinking I wouldn't really be able to do it that way, but would need to go the same route as was done for Pathfinder. Would that be a safe assessment?

I think you could do it within the d20 system if you wanted to. Capping HP is not hard, there are already adjustments you can look at to change that, and you could have a script set it to maximum Con x2 or current. For the martial feats, you'd need to make a unique special that is bootstrapped to every class in your system that detects the BAB, adds that number of feats to the feat tab, and has a script that requires at least an equal number of these "Martial" category feats or it throws a validation error. There must be a lot of these new feats, but entering them won't be more than data entry unless you want them to be reflected in the calculations of HL, in which case you can ask around on the forums here.

I have already created a .user file for adding the Martial Feats and setting their type to Martial (the program doesn't seem to have any issues with that, thankfully, although it does mean they show up as regular Feats and are selectable in the same way, so apparently I need to do some work to figure out how to make that not happen.)

As for calculations, that's going to be a big part of what I'll need, actually. I'll need to add fields that don't currently exist for Armor and Weapons as well as modify the rules for how Armor is allowed to layer (and how each component affects the layering). AC is also out the window for Codex Martialis, so I'd need to be able to hide that field or change it to something like "Bypass" instead (with a cap of 10 instead of 8). So if that's all doable that will make it easier for maintaining the d20 data files and working things out in .user files. Now I just have to figure out how to do all of that.:/

I'm not sure if anyone else is interested in this, or willing to help out with it, but here's an outline of a data plan for what would need to be done to get a Codex Martialis dataset into Hero Lab, I believe. If anyone is interested I'd certainly appreciate feedback or if there's anything I've missed here.

Codex Martialis Data Plan

HPs capped at CON*2
Separate Martial Feats table, although if we can work out Martial Feats requirements such that they are separated appropriately from standard Feats we could implement this within the Feats table.
Martial Feats gained at a rate of 1/BAB
Armor needs stats for Damage Reduction (Pierce/Bludgeon, Chop, Slash), Bypass, Speed, Hardness, Min. Strength, and Armor HPs. Armor Check, Weight and Cost stays the same.
Armor Components need stats for Stand-alone DR, Bypass Bonus, Armor Check, Speed, and Cost.
Components need layering rules accounted for and they need to be able to be equipped in addition to other Armor as well as on their own.
DR is highest of all worn. Bypass is determined by the adding of all components, rounding down.
Weapons need stats for Size, Reach To-Hit Bonus, Speed To-Hit Bonus, Weapon Defense Bonus, Armor Piercing Bonus, Attack Types, and Primary Attack, Grappling Bonus, Hardness, Hit Points. Damage, Cost and Weight works as is.
Shields need stats like Weapons, not armor. They need a note on the sheet to remind that they provide a Free Dice for Active Defense.
Ranged Weapons need stats for Ready Bonus, Max. Range, Prep Time, AP, Attack Type. Cost, Weight, Range Increment, Damage and STR Bonus applying remain.
Firearms additionally need Misfire and Tech Level. Bombs/Grenades also need Blast Radius added.
Ammunition needs to be added in a different way with stats for Cost, Weight, Range Modifier, To Hit Bonus, AP Modifier and Damage Modifier.
Unarmed is STHB: 6, RTHB: 0, Damage: 1d2, Ringen MF makes damage 1d3.
Danse De La Rue MF gives a Kick attack RTHB: 4, Dmg: 1d4 (STHB: -, as the attack is only available at Onset range)

Algorithms of note:
Weapon Onset To-Hit = RTHB + BAB
Weapon Melee To-Hit = STHB + BAB
Weapon Grapple To-Hit = BAB (+ STHB if have Half-staff MF for staff weapons, half-sword Fighting MF for certain swords and staves)
Base Defense = BAB + Dex Bonus
Active Defense = Base Defense + {(WDB or Shield DB, whichever is higher) OR (WDB + Off-Hand DB if have Main Gauche MF and if off-hand weapon is S or T, Max = 8) OR (WDB + Shield DB, if have the Shield Fighting MF and Weapon is size S or M, Max =8)}.
Active Missile Defense = Base Defense + Shield DB OR Base Defense + (WDB or Shield DB, whichever is higher, if have the Missile Parrying MF and only –v- Throw weapons)
Grapple Defense = Base Defense (+WDB if have Advanced Half-Word Fighting and using swords)
Passive Defense = Base Defense + 8 + Shield DB
Armor Bypass = Amor Bypass for Armor Set worn + Bypass for all Components added together and rounded down, MAX=10
Poll-Axe Fighting MF adds +2 to all pole arm WDBs and +1 STHB.
Pugilism = All Unarmed attacks increase 1 die-type in damage

The hiding of martial feats would be easy, just give them a source, so only users who want to use your Codex Martialis fields will click the source and reveal the feats.

For the rest, I don't see how you could do those things in the d20 system. You might very well have to use the authoring kit to build a new system. I am afraid I know little of that.

I think you misunderstand what I mean about hiding those Feats. Sourcing them is fine, but if I have it clicked as a source then I need those players to be able to only select Martial Feats when they get a BAB and not select any other Feats.

The confusion here is that Martial Feats are not in any way, shape or form anything like standard Feats. I use the term because it's how it's used in the the Codex Martialis, but maybe it would be better for clarity here to say that I need to have a separate "something" called Martial Styles. And you can select one of the styles for every point of BAB you have.

That's why I was suggesting something outside of the Feats mechanic. (Although many of these Styles do have Feat and/or Skill requirements, much like Feats, but they are not Feats and not supposed to be selected as Feats are, and Feats are not supposed to be selectable when with any of your available Styles slots.) I hope that makes it a little clearer.

Still, if the suggestion is that I would need to set this up as a new system I'll move this thread over to the appropriate forum for that. Thanks!

Since there isn't a way for a user to add a new table to HL (unless you start from scratch with the Skeleton Files and the Authoring Kit), I'd suggest figuring out what the closest approximation of these martial feats is in the existing files, and make use of that. It sounds like feats are going to be the best option.

So, you'll want to add a number of feat slots to the character equal to their BAB, then add an evalrule to require that the character have exactly that many martial feats (plus however many are added as bonus feats). This unfortunately leaves the martial feats in the same table as the regular feats, but a user won't be able to complete their character without fulfilling all the rules you've set up for the number of regular feats they're required to take and the number of martial feats they're required to take.

That's partially how I have it right now, although I would need to work out implementing adding the feat slots and setting up the evalrule. What about the rest of the plan, though. Do you think I'll need to do that through the Authoring Kit to really cover it all? I'm fine with going that route if that looks to be the best way to go. I'm just trying to prep everything for what I might need to look at doing to work on a project like this and while I've not had any problem messing with the data files in HL so far I do need to bone up on how to set up the evalrules and the like.

Before attempting to recreate the entire d20 files in order to make your own variant, I highly recommend you familiarize yourself further with the editor - see how much of this you can accomplish within the editor, and always think in terms of how you can set up a workaround that will let you present the correct information to the user, even if it doesn't look ideal.

Well, that's kind of why I posted that Data Plan. I'm fairly familiar with the editor already, at least for fairly basic stuff, but so far I'm not at all sure how to implement more than a few of the things above using that method. In order to implement CM I absolutely need to add new fields to Weapons and Armor and I need to be able to present those stats using the proper algorithm when shown on the sheets. I can live with presenting Martial Feats as a subgroup of Feats and expecting the player to properly distinguish between the two, but I'm not really sure how to do the workarounds for everything else. Using the Editor tends to be the least complex method to work from, but so far I'm having a hard time seeing how to use it to accomplish the above.