WARNING: EXTREMELY LONG AND DETAILED IDEA INCOMING
First off, Im a firm believer that every player in SOT should (geographically speaking) experience the same things to keep the world consistent. For example, islands should all appear the same to players to make everyone's stories and adventures relatable. The locations of each island and all large structures in the oceans shouldn't be randomly placed (like it already is) to allow players to learn the map and make consistent and accurate calls in terms of navigation.
However, I would enjoy some aspect of randomness and unpredictability when it comes to activities.
The Story
The most fearsome pirates in all the Sea of Thieves, the Skeleton Pirate Lords have hidden their most valuable treasures within an ever changing Labyrinth to prevent future generations from stealing their bounty. Rumor has it they still dwell among their riches to protect it from any pirate attempting to reach it. The Order of the Souls have discovered the entrance to these mysterious Labyrinths and created keys to open each one. The Order is calling all pirates to purchase the keys end descend deep into the unknown in search of these treasures.
The Details
Create an OOS mission type that would ask players to take on "The Labyrinth". This idea would ask players to purchase a Labyrinth Key from the OOS vendor, then travel to one of several tiny islands where you would enter an ever changing series of underground cave rooms to finally get to the final room where you would take on a skeleton pirate lord.
Think like The Underground in The Division or Phantasy Star Online 2 style procedurally generated rooms. There would be a dozen or so predesigned rooms with one or two variations to each room. Every time you enter The Labyrinth you would start with a different room and each room would be different than the previous. The order of the rooms would change each time you played it and the enemies and objectives of the room would vary in each room.
One cool aspect of this would be that things could offer platformer style experiences not currently in SOT. For example, certain rooms wouldn't require players to kill enemies to advance. Certain rooms could require a puzzle to be completed by the players, rooms could have deadly traps to avoid or certain rooms could have huge or difficult structures to traverse.
Imagine a room where you have to finish a puzzle while the room fills up with water, so you have to complete the puzzle or else you'll drown. Or a room where there are stone platforms you have to jump to and if you miss you'll fall to your death in a dark pit. Or a room you'll need to fire yourself out from a cannon to land on a swinging platform. There are so many fun ideas to think of for rooms that don't require killing enemies to proceed. The cool thing is, the dev's could craft new rooms and add them to the Labyrinth room pool later.
This could also be an awesome way to introduce skeleton lords into the game. If anyone has ever purchased or skimmed through the art book, you'll see an incredible amount of detail and variation in the skeleton lords. This could be a really cool way to give each skeleton lord their own time to shine. Each lord could have a unique boss room as well as a unique combat style. This could allow players to experience unique and otherwise impossible fights because the boss would be in an enclosed environment that could be completely manipulated by the boss. Each skeleton lord even appears to have visual/cosmetic ties to certain areas of the map (Shores of Plenty, Ancient Isles, The Wilds, Devils Roar). Let's say there is a Labyrinth island or two in each zone, then the boss you fight at the end could be tied to the zone you started The Labyrinth in. The zone you start The Labyrinth in could also be reflected in the visual style of the Labyrinth rooms or even its difficulty. For example, The Labyrinth in the Shores of Plenty could be beautiful and colorful and easy. But The Labyrinth in the Devil's Roar could be fiery and dark and more difficult than the rest. There's a lot of possibilities here for differentiation.
Once you get to the end and defeat the boss you'll get access to his treasure room. There you'll get some instant rewards for your hard work, like gold or a piece of a clothing set unique to that boss, as well as items you'll have to turn in like fort loot.
EDITED
So how do you prevent puppy guarding you ask? There are several ideas with some variation to them. Some of these were even created by others here in this thread! Thank you for your awesome ideas friends. So here we go...
- Idea #1: The Labyrinth islands could work like the island Thieves Haven where your ship can physically sail into the island through an entrance and settle at a dock. This is where some variations can occur. The first variation is that similar to Thieves Haven, your ship remains open to attack from other players but the island is fortified with cannons to protect your ship and there's only one way in and out. With this idea, similar to Forts, it would be smart to leave a player behind to defend your ship while others take on the Labyrinth. The second variation to this idea is that when you finally enter the island with your ship and use your key a great wall would rise at the entrance to the island and protect your ship until you defeat the boss or quit the mission. Then once you beat the boss and start carrying your loot back the wall would drop and you'd be vulnerable to attack again. As this wall rises, this would put you into a private instance and the server you left would fill your spot to keep the open world populated.
- Idea 2: Again, each Labyrinth Island would mimic Thieves Haven where you're able to physically sail your ship into the island. EXCEPT, the entrances to the island requires your ship to sail through a large waterfall to get to the center. Sailing through this waterfall would mask the server change and you would then enter a private instance to take on the Labyrinth and your spot in the open world would be replaced to keep the world populated. If you didn't have the proper Labyrinth mission purchased and proposed then trying to sail into the waterfall would either result in not transferring into a private server and you'd basically be sailing into an island with nothing for you and you could be followed in, or you couldn't sail through it at all. You would just crash into a rock wall. Either way, not having the mission activated would result in the islands not helping you in any way. Then once you're in the waterfall and the Labyrinth has begun, you're able to respawn at your ship safely!
No matter what idea is selected from above, this main dock in the center of the island could be creepy and cool and serve as a place to stock up before the upcoming Labyrinth adventure. The nice thing about any of these ideas too is it will still require the player to return to the open world servers with your loot to turn it in. This would keep everything in line with risk/reward system!
The End
This concludes my insanely long feature request! If you read it all, I commend you. If you have any additions or ideas to add I would love to hear it. Thank you all!
