Here are all the core mechanical changes I've decided on, which apply to everything. I'll add on anything when I make later decisions.
Actions use 4e-style action-spending, with Standard, Move, and Minor/Swift (favoring Minor, but undecided). You can spend a Standard to make a Move or Minor action, or spend a Move to make a Minor action.
Advantage and
Disadvantage are in, replacing simple circumstance modifiers. Fixed bonuses and such are still there, and extreme circumstances will still involve more significant modifiers, but this replaces all the fiddly +2/-2 mods. An advantage and a disadvantage cancel each other out, while two advantages vs one disadvantage leaves advantage on the roll, and vice versa.
AC is called
Defense, with subtypes of Ready and Unready Defense. (This is mostly because armor has little to do with how hard it is to hit you, instead mostly dealing with how much or little damage you take. This also means there's no difference between touch and normal AC, and flat-footed always struck me as clumsy terminology.)
Saves are still called saves, but they are sometimes also used as 4e-style passive defenses. The distinction between getting a save and using a defense is the difference of being able to affect the result with action points. (The format on the sheet is [defense]=10+[save]=[]+[]+[]+[]+etc..)
Action Points function much like in 3.5 Eberron/UA, with different costs. Spend 1 point to add 1d6 to a d20 roll (or better of 2 d6s lvls 11-20, or best of 3 d6s 21-30), spend 2 points to reroll a failed d20 roll, spend 3 points to get an extra Standard action on your turn. You can only do one AP expenditure per round, reset on the
end of your turn.
The Ability scores are called
Attribute scores. (this lets me free up the term 'Ability' as the counterpart for 4e's 'power', the generic term referencing any kind of spell, maneuver, or activated feat or class feature. I've also got an ability block format that hybridizes the colored rows of the 4e power block for easy reading and the more complex spell/power/maneuver format from 3e.)
- Strength: Add your Str modifier to melee and thrown damage rolls. One-handed weapons get 1x Str bonus, two-handed weapons get 2x Str bonus, while Str penalties are only applied 1x, even on 2-handed weapons. Your Str modifier also applies to Fortitude saves/defense.
- Dexterity: Add your Dex modifier to all weapon and weapon-like attack rolls, whether melee or ranged. Your Dex modifier also applies to Ready Defense, as well as Reflex saves/defense.
- Constitution: Add your Con score to your base hit points at first level. Your Con modifier also applies to every Hit Die you have. This applies retroactively if your Con score changes.
- Intellienge: Add your Int score to your number of skill points at first level. Your Int modifier also applies to the number of skill points gained each level.
- Wisdom: Add your Wis modifier to Ready Defense while no more than Lightly Armored. Your Wis modifier also applies to Will saves and defense.
- Charisma: Add your Cha modifier to the number of Action Points gained per-day. Your Cha modifier also applies to your Initiative roll.
Opportunity Attacks, by default, consume your Standard action from your upcoming turn. (The same way, in 3.5e, Immediate actions consume your Swifts. Haven't decided if this will also apply in GodsBlood.)
A high BAB doesn't grant iterative attacks anymore (in fact, the Full Attack is gone as a base action). Instead, at +6, +11, +16, etc, single-attack damage also increases by a factor of one on all basic weapon attacks. So if you deal 1d8+2 at +1 to +5 BAB, when you reach +6 BAB, you now deal 2d8+4, and at +11 BAB. you deal 3d8+6. This base damage multiplier increases every 5 points of BAB. At the same time (+6, +11, +16, etc), you gain one extra 'swing' (name will change, as this applies to ranged weapons and magic-based attacks as well) which allows you to retry an attack (any attack, even OAs) at the same attack bonus. When you use a swing to retry, however, you lose one multiplier to your base weapon damage. If this modifier gets to 0x, you're done retrying for this action. The retry function is what reduces the damage, not the spending of a swing, as there are other ways of spending swings, as well as ways of getting extra swings:
- Fighter-type classes (any full-BAB class) get one bonus swing at their 1st level, and the ability to spend swings to make OAs instead of burning their standard actions.
- The feat Combat Reflexes adds your Dex modifier to the number of swings you get in a round (minimum +1 swing, with the Dex 13 prereq).
- Two-Weapon Fighting grants additional BAB-derived swings for your off-hand weapon.
- Parry/Shield-Block actions allow you to make a skill check which replaces your Defense vs an attack, at the cost of a swing.
All speeds, distances, etc, are measured in Yards. To convert, use the Squares notation (5ft==1 square), but 1 square is treated as 1 yard/meter. This will have other effects, but base land speed of a human is most likely still 6 squares, for instance, that's just 6 yards (18 ft) instead of 30 ft. I'll get into it later, but this also affects space/reach for all the sizes. (small size reach is 1 yard, for instance, whereas medium size reach is 1-2 yards depending on weapon.)
There are both 3e-style Charge attacks (spend Standard+Move, move double speed and make attack with advantage) and 4e's charge, called Surge attacks (spend Standard, move speed and make attack with advantage). Both count as 'Charge' attacks for abilities which grant bonuses, but Surge gets half the effective benefits from such abilities (rounded down by bonus die, attack, or other functional unit, not by resulting damage or bonus). So for instance, the Powerful Charge feat (if it existed) would add +2d6 to a Charge, but only +1d6 to a Surge. If a lion got two Rake attacks on a charge, he would only get one Rake attack on a surge. If a minotaur gets one extra Gore attack on a charge, he doesn't get it on a surge. (these are all conjectural, for sake of making examples)
A Sidestep is a Move action that allows you to move 1 square (1 yard) without provoking OAs. (the free-action 5ft step is gone) Standing up from prone is likewise a Move action that doesn't provoke.
This is the basics for now, I'll add more if I think of it.