To start these side quests, you have to head to the assassination contract icon and open the pigeon pen to get the details about the target. You'll get a base reward and you'll even get a bonus if you're able to take out the target undetected. In case you made a blunder and you get detected by any means (even getting into a fight with the guards outside the target area), your target will catch on and will temporarily flee. You have to wait until he returns to the location or just simply do a fast-travel to the nearest viewpoint and your target will be back in his position. Fast-traveling is also a good way of “resetting” an assassination target especially if you're after the bonus reward for staying out of combat.
Once near the area, you can use your eagle vision to identify the hostiles and the target itself, which will be highlighted yellow. You'll get the bonus as long as you kill your target before causing an uproar.
Here's the list of all the assassination contracts in the game. There are 30 of them and to make it easier for you, their guides will be sorted per location.
- The Plantation Master
- The Guard Post
- The Slave Traders
- The Judge
- The Weapons Smugglers
- The British Captain
- Beach Bonfire
- A Shipment of Powder
- The Spanish Commander
- Unlicensed Dealer
- No More Taxes
- A Botched Escape
- The Pirate Captain
- The Outlaws
- Tomb Raiders
- A Last Drink for the Road
- Castaway
- The Unworthy Brother
- The Poachers
- The Deserter
- The Twin Dilemma
- The Dreaded Pirate
- The Expedition
- The Slave Master
- A Slaver's Business
- The Informant
- The Treasure Hunter
- Shady Business
- The Smuggler's Squat
- The Outlaw's Cave