This is rather complex to explain and involves two separate mechanics.
Part 1:
In the original Star Wars: Galaxies, each character had access to a bunch of different classes that you could level up with different kinds of experience. Experience was banked and used to 'buy' levels in the classes that used that kind of experience, and sometimes you needed more than one type of experience to buy a particular level. Most characters were a combination of levels from several different classes using several different kinds of experience.
There was a limit to how much experience of a given type that you could bank that was based on the number of levels you had in certain classes, and there was a limit to how many total levels you could take at once across all of your classes. It was also possible to 'forget' levels to allow you to respec and change up your build, but you'd lose the experience you spent on those levels. If you had experience banked and 'forgot' levels that brought your maximum experience below what you already had, you'd lose the excess. However, critically, this loss wouldn't be triggered until the next time the experience counter for that type changed, either by gaining experience or trying to spend it on a level.
Part 2:
SW:G had a faction system that allowed you to take missions from and ally with different groups in the Star Wars universe. The two main factions were, obviously, the Empire and the Rebellion. Completing missions for these factions gave you faction points that you could spend on a variety of things including special items, vehicles, resources, and faction-specific cosmetic or combat pets. You could also trade in your faction points for experience at a rather painful rate, something like 100 faction points per 1 experience point.
Here's where the exploit comes in:
If you have a lot of experienced banked in an experience type in which you have a lot of levels, when you 'forget' those levels, you'll end up with a bunch of surplus experience that you can't use, and that will be lost the next time you gain or spend experience of that category.
When you purchase experience for faction points, your faction point counter is decreased in increments of 100 points, and your experience counter is increased in increments of one point. While clearly not intended, this function also worked in reverse.
Therefore, if your experience went down during a faction point transaction, your faction points would go up by 100 times the amount of experience. If you dropped a bunch of levels, then use faction points to buy 1xp in that experience category, all of your banked experience above the limit would disappear, and your faction points would be increased by the number of experienced points removed times 100.
This allowed you to generate hilarious numbers of faction points by sacrificing experience.
What made this an exploit was what you could buy with the faction points. The most expensive items you could buy were the combat pets. Imperial allies could buy AT-STs to follow them around and blast the shit out of everything. They cost several tens of thousands of faction points each, and were intended as a major reward for someone who committed to grinding Imperial missions for a long period of time.
With this exploit, you could turn a couple hours of grinding experience into hundreds of thousands of faction points and buy a bunch of AT-STs to kill everything around you. I think there was a limit to how many pets you could have out at once, but that just meant that you'd have spares.
I personally bought 5 AT-STs with this exploit, went to Tattooine, and soloed Krayt Dragons for a few days before finally getting bored with the whole thing and quitting the game.
This is rather complex to explain and involves two separate mechanics.
Part 1:
In the original Star Wars: Galaxies, each character had access to a bunch of different classes that you could level up with different kinds of experience. Experience was banked and used to 'buy' levels in the classes that used that kind of experience, and sometimes you needed more than one type of experience to buy a particular level. Most characters were a combination of levels from several different classes using several different kinds of experience.
There was a limit to how much experience of a given type that you could bank that was based on the number of levels you had in certain classes, and there was a limit to how many total levels you could take at once across all of your classes. It was also possible to 'forget' levels to allow you to respec and change up your build, but you'd lose the experience you spent on those levels. If you had experience banked and 'forgot' levels that brought your maximum experience below what you already had, you'd lose the excess. However, critically, this loss wouldn't be triggered until the next time the experience counter for that type changed, either by gaining experience or trying to spend it on a level.
Part 2:
SW:G had a faction system that allowed you to take missions from and ally with different groups in the Star Wars universe. The two main factions were, obviously, the Empire and the Rebellion. Completing missions for these factions gave you faction points that you could spend on a variety of things including special items, vehicles, resources, and faction-specific cosmetic or combat pets. You could also trade in your faction points for experience at a rather painful rate, something like 100 faction points per 1 experience point.
Here's where the exploit comes in:
If you have a lot of experienced banked in an experience type in which you have a lot of levels, when you 'forget' those levels, you'll end up with a bunch of surplus experience that you can't use, and that will be lost the next time you gain or spend experience of that category.
When you purchase experience for faction points, your faction point counter is decreased in increments of 100 points, and your experience counter is increased in increments of one point. While clearly not intended, this function also worked in reverse.
Therefore, if your experience went down during a faction point transaction, your faction points would go up by 100 times the amount of experience. If you dropped a bunch of levels, then use faction points to buy 1xp in that experience category, all of your banked experience above the limit would disappear, and your faction points would be increased by the number of experienced points removed times 100.
This allowed you to generate hilarious numbers of faction points by sacrificing experience.
What made this an exploit was what you could buy with the faction points. The most expensive items you could buy were the combat pets. Imperial allies could buy AT-STs to follow them around and blast the shit out of everything. They cost several tens of thousands of faction points each, and were intended as a major reward for someone who committed to grinding Imperial missions for a long period of time.
With this exploit, you could turn a couple hours of grinding experience into hundreds of thousands of faction points and buy a bunch of AT-STs to kill everything around you. I think there was a limit to how many pets you could have out at once, but that just meant that you'd have spares.
I personally bought 5 AT-STs with this exploit, went to Tattooine, and soloed Krayt Dragons for a few days before finally getting bored with the whole thing and quitting the game.