Lost Ark will send players on an assortment of adventures. Along the way they will be leveling up their classes and shall be learning all manner of abilities. Lost Ark has five different classes, and each of those has three different subclasses.
If you are wondering if you can change your class in the game, then the answer is no. Once you pick your class, and your subclass, that is it, you are locked in in that character. While that might sound rough, you can start a new subclass just by starting a new character, and you can use a Powerpass to speed up the process in some cases.
There is also an important factor to consider, which is that Lost Ark is extremely generous when it comes to changing around your abilities. You can actually change all your abilities and where you have your skill points whenever you like.
As such, you can experiment with your class almost endless, and set up multiple skill trees that you can quickly switch over to, allowing you to set up a character with different builds depending on what you want to do in the game. Need huge single-target damage? Not a problem, you can just set up that skill page, then switch to it whenever you like.
So, while you cannot actually change the subclass of your character, that is quite standard for games of this type. But, in many ways, Lost Ark is very respectful of players’ time, giving them as much freedom as possible when it comes to playing with builds.