In a nutshell my classless system (based on 5e/pf1/pf2/OSR) works like this:
1) at each level the character gets 1 point to increase magical ability or skill with weapons (BaB)
2) every 2 levels takes a feat that somehow resembles class ability
3) many feats can be taken more time to improve the feat or gain new correlated ability
4) depending on the type of feat (more combat, magical, spiritual ..) the related saving throws increase
5) hit points are equal to 4 + Constitution bonus , + 3 if you have increased combat capacity
6) the points on combat competence can be given to homogeneous lists of weapons and more points you have dedicated to the same list the greater capabilities this grants you
7) depending on your magical ability you have access to more spell points and higher spell levels
and much more... but in italian...
TUS/OBSS.pdf at master · buzzqw/TUS
BHH