There are many differing opinions on Stat distribution in ToS and currently no clear-cut superior option however there are a few trends and considerations I will go through.
An indepth description of all the stats and substats can be found on tosbase wiki.
Pure Str or Int. Your abilities will mostly gain bonus from STR, however this bonus is flat. For example, Str resulting in 81 Physical Attack will add literally 81 Damage to the end of calculation. STR also increase critical damage however you’re not going to be critting much with a purely STR build.
Pure Dex for Physical Classes (Magic can’t crit btw). There are 2 reasons for this, Evasion and Critical. There are 2 considerations for this, firstly as you level up so will enemies stats so to keep critting and evading you will need a lot of dex, secondly you can’t evade magic.
Pure Con. Outside of a few skills all the bonus damage from STR or INT is a flat increase with most of the damage coming from skill ups, some players choose to pump just CON only. This is a much rarer option but I believe is valid even for non-tanking oriented builds.
SPR. Full Support Clerics usually go Full SPR or some mix of SPR and CON because of many Cleric skills scaling with SPR. Besides Clerics some people like to get some SPR for SP and SP regeneration but with the availability of recovery items I’d advise against this.
Content Considerations: PvE
Accuracy: I’ve seen people concerned about Dex levels in regards to being able to hit monsters. There is gear available for people to gain enough accuracy to never touch Dex so outside of Critical/Evasion builds, there is not much reason for Dex.
HP: People have been worried about HP required to stay alive in PvE content. From my own experiences and looking at how others survive at higher levels I’ve seen anywhere from no CON to 50ish CON to full on CON and nothing else. This one I believe is personal preference, just see how you go and add some if you need. A factor to consider is the main Cleric healing skills work based on percentage of health so the more health you have the more effective healing is.
Content Considerations: PvP
PvP is dynamic so its hard to give a certain answer and this may depend on classes as well. But here are some example things to think about.
Accuracy, how much accuracy will you need against your average PvPer? Are Evasion builds popular?
HP, You will always need some extra HP for PvP as you can’t control who the enemy is going to hit outside of spacing and positioning yourself. If a Catapract impales you and pulls you towards their team, you’ll need to be able to survive that or you’ll end up doing nothing.
STR/INT, This I believe after considering the above is as much as you can get without neglecting the above too much.
How much accuracy and HP you need before you can pump offensive stats will depend on the metagame – You will want to build around what everyone else is doing, because well you want to beat them right? As of now in Korean Tree of Savior, evasion builds arent’ popular because magic is popular and well, evasion can’t dodge magic so you can probably get away with little to no dex.
PvP is a complex topic on its own I will discuss in another article.