Wasteland 3

you can get exp from complete quests,kill enemies, pass skill check (unlock lock,hack computer,kiss ass,hard ass,etc.).To get level 25,I suggest you create a Ranger have max charisma from game start,and study picklock nerd stuff and mechanics skills,and use this guy to pass more check as possible,and do the all side quest.I belive you can get level 25 before game ending.