I find it interesting that my three projects have formed up with three different flavors of combat action.
One uses a three phase system that is solidly old school, while being moderately chunky. Perhaps a B/X equivalency.
One uses a five phase system that pulls a great deal of inspiration from the earliest rules, including Chainmail. It involves more choices and is as involved as AD&D.
And the last uses a system with very short rounds that feels much more modern than the others. It’s intended to feel very pulpish and is the easiest of the three to wrangle.
I’ve one that’s a riff on D&D, leaning towards AD&D. It’s being written as a series of modular sub-systems that folks can swap for the RAW sub-systems as they wish. Once they’re all finished and released individually, then I’ll knit them together as a single entity for release. The individual modular bits as presented should work with the existing RAW without issue; once the whole is assembled, some of the rules will be incompatible with the existant RAW. I’m bringing some of the wargames elements of early play back into the rules as I believe their loss has been to the detriment of play, if only because they bring options that aren’t supported by later editions (split-move & fire, similar actions).
The next project is a bespoke fantasy game designed from the beginning to play in the same space as D&D. It has a consistent design ethos instead of being a pile of accumulated mechanics and sub-systems and patches. It also take different approaches to many of the sub-systems: magic involves channeling mana to cast spells; damage accumulates and can cause wounds, with checks for capacity at intervals until the character is incapacitated (no specific threshold for incapacity); the same range of combat actions expressly supported as with the first project.
The last is intended for pulp-style play with characters already a bit larger-than-life at the outset. It uses an OpenD6-ish resolution system to allow for larger-than-life feats as a regular part of play. If a table wants to have Conan-esque combat with limbs getting chopped off right and left, this system will support that.
The reason I ended up with three projects concurrent has to do with my brain bubbling up bits & pieces that don’t all fit together in one project. The bits are interesting and certainly worthy of use, just in a different setting than the bespoke system. So the D&D riff got started with some of those bits. Then, later bits jumpstarted the pulp system. I can now have something bubble up and am more likely to find a place where it fits from among the three.
Example: Had thoughts on straight up magical dueling crop up last week. The first two projects already have casting and counterspell mechanics, so I’m now looking to see if the magical dueling fits in with them – I know it doesn’t fit with the pulp system. The mana channeling magic sub-system is already a major change to D&D, so perhaps expanding the magic rules further in the D&D riff would be a bit much for folks to accept (though it could always be presented as an optional expansion). The full magic sub-system certainly belongs in the bespoke game system.