What You Get Better At
In one sense, Mythmaster is a game about characters in search of adventure. The core appeal of the fantasy is escapist in nature - we seek something more fulfilling than the banalities of an everyday existence, but commitments and risk aversion constrain us. To manage this existential dread, we entertain ourselves by pretending to be charaters who seek the same thing, but in an imaginary context where the commitments and risks may be many times greater - but the consequences are imaginary. What a fantastic thing play is!
But play can also be more than mere escapism. In its nature, play is a kind of self-reinforcing learning, and any time you play, you are getting better at something. So in a different sense than that above, we can say that games are 'about' whatever it is you get better at when playing them. Looking at play in general, and Mythmaster specifically, it is interesting to ask the question, "what do I get better at when playing Mythmaster?".
Progression (what your character gets better at)
Many tabletop RPGs focus heavily on character progression: fighting monsters to earn experience points to level up your character and unlock new abilities. Typically, low level characters need to worry about badgers and hobgoblins and high level characters fight demons and dragons. A high level character might be 100x more powerful than they were at the beginning.
Breadth versus Depth
Mythmaster has some of this progression, but not to the extent described above. In Mythmaster, a weak, young character might be be dangerously outmatched by a single hobgoblin, but even a powerful hero with two decades of experience and a dozen wars behind them could be overwealmed by small band of them using combined tactics and a range of abilities, and going toe-to-toe with a demon is almost certain death. This is because progression in Mythmaster is not strongly anchored to DPS and HP (damage per second and hit points), but instead encourages characters to develop a breadth of skills and to add new abilities that can combine with their existing abilities in interesting ways. Rather than gaining more health, more attacks, and more damage each time you level up, you character will gain small improvements to their stats and attributes as they increase their mastery in different skill fields by broadening and deepening their skills.
Types of Simulated Conflict
Because Mythmaster's progression is less about dealing and taking physical damage and more about broadening your character's capability, the game also needs to support different types of conflict. Conflict in Mythmaster does not need to center on physical combat. In fact, there are many interesting ways to make characters who simply cannot fight at all.
In Mythmaster, a significant bulk of the rules are devoted to things like social conflict, investigation, diplomacy, and negotiation. Conflict can be resolved by intimidation, humiliation or confusion often just as efficently as through force of arms. A few well-considered skill rolls that goad an enemy into doing something foolish or dangerous can be as effective as well-placed poisoned arrow or full on cavalry charge.
Skill (what you get better at)
As your character progresses, new skills and perks will become available to them - and with these new skills and perks come new ways to play. The more experienced your character, the more opportunities you will have to use your character's abilities in combination, and to counter the abilities of your character's opponents.
Play and Counterplay
Play and counterplay are important in Mythmaster, and with experienced characters, confronting the challenges of the game effectively requires a certain amount of skill. While Mythmaster allows players to create very experienced characters from the very beginning, it is important to understand that experienced charaters are not 'powerful' unless they are played well by skilled players. As you progress you character in Mythmaster, be sure to take the time to read the descriptions of your new skills and abilities carefully, and make sure you understand how they work.
What You Take With You
Playing Mythmaster you will inevitably get better at the hard skills of the game such as optimizing character builds, matching weapons and attacks against armour and defenses, and learning to counter enemies effectively. These skills are specific to Mythmaster the way skating while managing a rubber disk with a stick are specific to hockey. The skills that matter most whenever we engage with a game are those skills we take with us when we leave the magic circle of the ice rink or the gaming table behind and return to our real lives.
Mythmaster, and tabletop roleplay games in general, are collectively negotiated, creative play spaces. Engaging in table-top role playing games will help you develop many other valuable skills including self-confidence, role-playing, public speaking, problem-solving, co-operation, storytelling, and independent thinking.