The Legends system is a feature in that rewards players with cosmetics or gameplay bonuses in the form of Mementos. The system incentivizes completion of campaigns in their entirety and tracks accomplishments across multiple games, and it comes in response to a key data point that highlights a big problem with previous games.
Legends give clearer incentives for continuing or completing a campaign and are organized into Paths where players will gradually unlock rewards based on experience and completing Challenges, which are divided into two distinct categories: Leader and Foundation Challenges.
Rewards for completing these Challenges come in the form of Cosmetic awards and Mementos, items used during gameplay to boost specific abilities or award specific bonuses.
Cosmetic Collectibles include Badges, Banners, Borders, and other customizable esthetics for the Player Card. Mementos range in their effects and are selected at the beginning of a campaign to provide unique bonuses for each player.
Many of the Challenges in the Legends paths will be naturally unlocked as players spend time playing the game, while others require specific conditions to be met.