First of all, the whole skill system is still subject to review and testing. There's the possibility of heavy changes over anything I mention here.
It is evident that all skills depend on one or several traits (e.g. heavy weapons on Str, light weapons on Str+Dex, ranged weapons on Dex+Awa, "maps & charts" on Awa+Int, etc.). Now, based on the character sheet of one burly bodyguard named Harry_273, it appears that unarmed combat is solely based on dexterity, and not a combination of dexterity and strength. If this is so, why? Why would I need Str+Dex when wielding a knife, but no strength at all when boxing and wrestling?
Every skill depends on a primary and a secondary trait. On the secondary trait, bonus is halved. Martial Arts has Dex + Slf as traits. Str may not influence your ability to hit with martial arts, but it is still very influential to calculate damage and for other factors.
Furthermore: Harry_273 (did the previous 272 Harrys die, by the way?) has one rank in the skill Dodge. However, his total value is "-". How does this work?
Dodge skill contributes to passive avoidance. Its effects will be fully explained when you hover over the avoidance value or the dodge skill. and yes, Avoidance is also affected by Dex and Awa, as well as by any unspent Action Points on your character (if he already acted that turn, which makes winning initiative very useful).
the reason why it shows as "-" is because avoidance has its own value listed on the character sheet, but probably still wasn't working when the screenshot was taken.
Besides avoidance (which is indeed "speed-based" and negates all damage) you have armor, which negates a portion of the damage you receive from hits.
Also: What is SLF? "Self"? If so, what does that mean?
Self-Control. How much the character's Mind rules the Body, the ability to push harder in pursuit of some goal, or draw upon the inner reserves of strength to overcome challenges.
And finally: Why is the batrax caster in the artwork wearing clothing? All the batrax in Exiled Kingdoms were nude.
Batrax wear clothes for the very same reasons we do. These Batrax intend to live permanently on the surface, not just to prey on it for a few hours, and clothing is a convenient protection from elements and other dangers, and provides social utility.
Edit: I will reproduce part of my replies at the 'Dex as well...