At first, the engine will have the default battle system from 2003 with some basic fixes (agility!). Then I will add the turn-based FFX-style order list to let you make 2000-like games (with battlers visible if you added battle charsets for them). Multi-hit attacks are already possible in 2003, I remember making a sword that hit six times.

You should probably just assume a 2003 battle with the ability for global battle events. Apart from that, you can always check the syscall page up there as they work during battle. Once you have a battle engine in your hands and it works, then you can see additions and stuff being made to it. Because of the global battle event page, you could easily modify your game to add any extra features you feel you need. Oh and it's going to be much faster! My speed inversion might make your battles a little too fast so you can always adjust the speed using the syscall.

It's an abbreviation for system call.

I made a list here

There's an explanation for how you use it. It's done this way so I can extend the engine with lots of extra commands to make things easier.

"absorption of elemental attacks."

I think 2k3 already did this, you could type negative numbers in the attribute effects.

"Also, the way elemental weakness works in the dbs is wonky. If the target is weak against one element in a multi-element spell, the spell will always do damage as if he was weak to it, even if he was resistant to all the other elements in an attack."

I'll have to preserve lots of the behavior of the default battle system otherwise it will break lots of games for people unexpectedly. I'll consider how to switch DBSs and how to configure them after the first ATB DBS has been made and bug fixed.

"Also, casting offensive magic on friendly targets, and defensive magic on enemies. Kind of in conjunction with the above, making undead weak against healing magic and having the ability to cast healing magic on them would be cool."

This however I think I'm going to have.

"Having skills that cause stat lowering on the user in addition to effects on the target would be nice too. Y'know, using powerful magic that halves your INT after use as it's drawback. Or having skills that put status effects on the user or his allies. (regen?) Or skills that put a status effect on the user in addition to attacking the enemy (paralyze you after a massive attack, or whatever)."

I know, but I'll figure these out after the first DBS has been completed. I love going insane with scope creep, but it's nicer to do when I've finished the battle system itself to begin with first.

"if you somehow added panorama layers that would be pretty rad."

I was thinking of actually doing auto-previous-level-parallax or whatever.. Don't know what I'll call it. This is when the map before this map in the tree in the same level is drawn zoomed out as the parallax. The actual below map becomes the parallax so you could do tower or mountain levels.

Either way, parallax layers is also something I want to implement so you could replicate the old school 3D-ish HUGE TRACKS O LAND scenes where they used H-Blank to shift the map each scanline and added cloud layers.

Or I could actually emulate H-Blank effects so you can take one parallax and define scrolling offsets for each scanline.