Unbound Tales does not use a conventional XP system. Characters earn milestones by completing encounters, and then taking time to reflect on their accomplishments.

Whenever a party completes an encounter, they will gain Victories. Easy encounters are only worth half a Victory; Moderate encounters are worth one Victory. Challenging encounters are worth two Victories, and Deadly encounters are worth three Victories.

Victories serve two purposes. First, if the party begins another encounter, they will typically gain benefits according to the number of Victories that they have accumulated. The exact benefit depends on their class; for example, a Berserker receives temporary stamina based on their current Victories, whereas a Mage starts with some Æther in reserve.

Second, when a party Takes a Short Rest, one of their Victories is converted into a Milestone, and added to each character's sheet. When they Take a Long Rest or Take Down Time, all their Victories are converted to Milestones. Fractions are dropped.

When a character accumulates sufficient Milestones, they can Upgrade their Character. This requires that they expend Milestones equal to four plus their character's level.

Characters can gain Milestones for completing storylines. When the party completes a storyline, they should gain one Milestone, plus one additional Milestone if they met the storyline's victory condition. Not every storyline must have a victory condition; those that don't, do not assign the victory Milestone.