Infinite Skill Points
To use this exploit, you need two things: a sufficiently high-level ranger, and a rank 8 skill – this is because a skill rank cannot be a higher rank than the ranger’s level. If you are going to use this exploit, why not go for Exploit #1 first and hit the max level?
The easiest skill to get to rank 8 is Gambling. The Swim skill is also easy to get to rank 10, but it’s dangerous.
Once you get either of these skills to rank 8, head to a library. While in the library, the rank 8 skill will state that it needs 255 Skill Points to rank up. In actuality, the game treats this as a -1 (negative 1).
So just try to rank up the rank 8 skill. Not only will it become a rank 9 skill, but you will also gain a skill point on that ranger. In fact, max this skill rank out! (Note you can’t have more than 255 skill points, so stop before you reach 255).
But it gets better! Take all those free skill points, and strategically use them to raise another skill to rank 8. Repeat the process and gain even more free skill points!
Caution: The original game (haven’t confirmed in the Remaster) allows each ranger to have a maximum of 30 unique skills. If you took your 30th skill, the Librarians would kick you out stating they have nothing left to teach you. At which point, you will no longer be able to use this exploit.
So the true max number of unique skills is 29. But you really don’t even need that, unless you are being greedy, because about a third of the skills available are ‘specialized’ skills. Specialized skills are skills only a single ranger on your team needs to take. As long you spread the specialized skills around, you won’t be anywhere near 30 unique skills.