EN: Each towers has their own, unique skill tree. The more engaged in combat they are, the quicker they will gain experience. When they level up they gain a skill point which can be allocated in their tree.
每个塔都有自己独特的技能树。参与战斗越多，获得经验的速度就越快。当它们升级时，会获得一个技能点，可以在它们的技能树中分配。
chatgpt (sanity-fix by PhroZenOne)