Advancement
Every creature has a level that determines their general level of power and control over the world around them, including their experience, knowledge, luck, skill, strength, etc. When you create a character, they begin at 1st level with a small package of abilities and proficiencies, representing a normal person with only some basic training but plenty of potential.
Every time a character accomplishes feats of heroism, derring-do, or other intriguing accomplishments in the story, they gain rewards such as surges, experience points (XP), and exploits.
When a character accumulates 100 or more XP, they reduce their current XP pool by 100 and increase their level by 1. Each time they level up, they gain additional benefits as noted on the table below.
Some effects can reduce a character's XP, even putting it into a negative value. While a character has a negative XP value, they cannot gain surges, but increase their XP pool by the number of surges they would've gained instead.
EXPERIENCE
The completion of a mission gets you XP depending on how difficult it was. Once you've accumulated 100 XP, you level up, reduce your XP by 100, and essentially start over.
Learning from your Mistakes: During encounters that are life-threatening and average difficulty or worse, you can choose to turn one attack, recovery, or skill roll you make opposing a dangerous foe or obstacle into one degree less successful than it actually was (critical success --> success --> failure --> critical failure). You get +1 XP per time you do so (+2 if Hard, +3 if Very Hard, +4 if Overwhelming) to a max of 3 times per scene.
Advancement Table
Abilities
At 1st level, you begin with 3 special abilities of your choice and 3 from your origin (possibly more if the origin came with weaknesses). Every level thereafter you can gain a new ability of your choice or upgrade an existing ability.
At every even level after 1st (2nd, 4th, 6th, 8th, etc.), you can increase the rank of one of your existing abilities by 1. If all your abilities are already maxed, you can bank this upgrade until you gain an ability that can be ranked up.
Attributes
At 5th and 15th level, you increase 3 attributes of your choice by 1. At 10th and 20th level you increase all of your attributes by 1.
Proficiencies
At 1st level you begin trained in 3 defenses and (5 + INT) skills of your choice.
At every level after 1st (2nd, 3rd, 4th, 5th, etc.), you can increase your proficiency rank in one skill of your choice up to a maximum of trained.
At every odd level after 1st (3rd, 5th, 7th, 9th, etc.), you can increase your proficiency rank in one defense of your choice up to a maximum of trained.
This maximum increases to versed at 5th level, expert at 10th level, master at 15th level, and legendary at 20th level.