The character stats are very simply to understand and master: health, attack and speed. As one would expect, increasing health points will boost your maximum hit points. Attack determines how much damage your character will deal out per strike. Lastly, speed is the factor that determines how fast your character attacks.
Since health is pretty much straightforward, we will not go into detail with that (in fact, if you improve armor occasionally enough, you will not have to invest a single stat point on health), also health increases a bit per level.
Balancing out speed with attack is a matter of doing a bit of math. But for the most part, being able to attack 20 points of damage 5 times in two seconds than dealing 100 points of damage in two seconds is considered a good idea; the reason for this is the presence of critical hits. Sure, if you are truly lucky, you can deal 200 damage with the 1-hit attack, but a successful critical hit only occurs 20% of the time (if you have the critical jewel fully upgraded). On the other hand, if you can attack 20 points of damage 5 times in two seconds, then you will have 5 chances of landing a critical hit. Sure, the chances of all five being criticals is low, but statistics would state that you are more likely to get at least one critical (which means your damage per 2 seconds would be 120). Of course, the final decision on how to build your character is still entirely up to you.
Aside from assigning stat points, players also get to choose perks –which are basically multipliers. Multipliers will increase the stat by a specific percentage, and while it may not seem like much at first, the change is quite noticeable once you have placed plenty of perks on a single stat (while you can add 5 points per level, a massive 10% boost to a stat can do the same thing). This means that aside from distributing the stat points, you can also bring in the perks to the equation –as it certainly helps increase other stats that you are not focusing on.