Black Flag Resynced introduces new content and modifications to the original game, including new sidequests and enhancements to combat, stealth mechanics, and ship features. Key facts include:
- Mayan Stones provide a Trinket that absorbs gunfire, in addition to Mayan Armor.
- Players can no longer pick up enemy weapons.
- Hidden blade combat is limited to finishers only.
- Stealth missions have no fail conditions if detected.
- The Jackdaw's Ship Plans are now called Ultimate Plans, and Treasure Maps have changed.
- New combat tool: Rope Dart, available in Sequence 3.
- Sequence 4 unlocks several quests, including Art Lover, two officer quests (A Second Chance and A Proper Shipwright), Rifts, Animus Projects, and two new pets (Soot the Cat and Albert the Monkey).
- Blackbeard's Treasure sidequest activates after completing Do Not Go Gently in Sequence 8.
- Captain Stede Bonnet sidequest becomes available after Marooned in Sequence 8.
- A World Without Gold chapter and an additional officer quest unlock after completing Everything is Permitted in Sequence 11, leading to further quests and a new mortar type for the Jackdaw.