My apologies if you're already aware of any these things or if I've strayed into parts of the game that aren't ready for playtesting.
Everything is out there for playtesting. If I did not want playtesting, I wouldn't release it.
Some of the changes from standard D20 are a bit jarring and seem poorly explained; this is probably just because I'm so familiar with D20.
From my point of view, your familiarity with D20 is a very good thing!
EDIT: Aside from Combat Casting bonus not being applied properly and the max spells per day limit not being enforced, all other issues were fixed!
I don't know if they're intentional or not: magic missiles apparently allow a fortitude save for half damage;
This was a side-effect of reworking the damage types to allow saves automatically. I liked it (d20's version is "deduct hit points directly", as the joke goes), so I kept it. (Will note it on github's page listing changes from standard SRD)
wizards aren't proficient with quarterstaffs; rogues aren't proficient with rapiers;
I forgot about this one, and frankly I'm of two minds whether to implement it or not (the goal is to get rid of most if not all those "special" cases and "no one else can but I can" stuff so that it is more transparent for people who do not know d20's quirks).
dual-wielding a dagger and quarterstaff is permitted.
Not intended, obviously, will fix it in a moment.
Combat Casting appears to count as skill ranks instead of a bonus on top of skill ranks.
Will look into it (obviously, the intention is to have it applied on top of skill ranks).
Weapon weights are incomplete? (A longsword weighs more than a greatsword.)
Probably a copy&paste mistake, easy to fix.
A few bugs: Limits on skill ranks appear to be 4 plus level (i.e., 5 at level 1) rather than 4 at level 1.
I fail Maths for ever. I've got no idea how I managed to get straight B's in high school with the number of blunders I've made in 4 years since. Fix coming as soon as I open the files.
There seems to be no limit on how many spells a wizard can prepare.
Known issue. I've been badgering Sebsebeleb about it for some time (I don't understand the spellbook code enough).
My summoned wolf (or was it a badger?) had a attack penalty of -4 and a damage penalty of some sort, making him pretty useless in a fight.
It had some placeholder stats instead of proper ones. Will fix.
Rings of protection don't actually increase AC. AC seems too high across the board; my drow wizard with dex 11 started with an AC of 16, and many opponents seem to have ACs of 18 or more, so combat seems like a bunch of misses until someone gets lucky.
I will look into AC again. Most probably some bonus gets applied twice.
Last but not least:
The character leaves a trail of lit squares behind him. This is a bug in the example module. Adding the following code to Player.lua fixes it. (I know this only because I recently fixed the same problem in my module.)
game.level.map.clean_fov = true
Thanks for pointing this out, fix incoming!
P.S. Seriously, feel free to playtest. I am trying to test every release, but I can't study, code and test at the same time, obviously. So studying comes first, coding comes second and, well, testing comes last.