Perks

A character begins with a set of perks. These are unique features only granted at 1st level to help give a character the tools it needs to succeed without needing to be granted by a class. Perks primarily allow a character to use their ability scores in new ways from adjusting what stat governs a saving throw, to the stat used in melee attack rolls.

Drawbacks are also an option for characters; while being called drawbacks work similarly to perks but provide some sort of character-defining detriment alongside a much more powerful than usual bonus.

Perks and Drawbacks are both split into categories of Major and Minor. At 1st level a character begins with one Major Perk and Two Minor Perks; and may select a Single Major Drawback or up to two minor drawbacks. Characters may substitute perks with a drawback of similar category (major drawback for a major perk, minor drawback for a minor perk), but do not gain anything extra for doing so beyond the listed benefit for taking the drawback.

Perks
Major perks tend to do a full conversion of an ability (such as changing will saves from focus to psyche); while minor perks tend to do a partial conversion (such as weapon finesse allowing agility for melee attack rolls, but still using strength for damage rolls). These can be more than expanding or replacing the usage of a stat but tend to be build-defining.

Drawbacks
Drawbacks are character-defining traits that have both a positive and negative affect on your character. These may be taken in place of perks; marked individually as a major or minor drawback. Drawbacks are designed to have a negative impact on your character, but as a trade should give a benefit that either balances against the drawback or at least allows a character to cope with the drawback better than others. This is generally a system to facilitate thematics rather than allotting raw power to a character, but as the character is gaining benefits some restrictions do exist on this as well.

Characters are normally allotted 1 major drawback or 2 minor drawbacks in addition to their normal perk selections. These do not allow a character to take additional major or minor perks beyond their normal limits, and instead are taken in place of their listed type, major drawbacks in place of major perks and minor drawbacks in place of minor perks. A GM may allow a player to take more drawbacks beyond the normal allotment without needing to trade their perks.