Updated in 2024 - Made Easier to Read

https://steamproxy.net/app/582160/discussions/0/1729837292625258725/
I just made it into a guide so it can be easily found also

Hidden Blade: If you're early game you'll get it later when you progress in the story more Incapacitating your enemy does NOT count

Costs 2 Ability Points to gain access to its feature

3 minutes after your last Assassination
Exploit: Pausing the game by pressing ESC or opening the character menu DOES keep track of the time, say I entered the ability screen & waited for 3+ minutes, when exiting the menu & entering the live game, you will be awarded your bonus for however many assassination kills you got without being detected

Meditating to change the time of day does NOT skip time to award your experience immediately

Fast traveling actually resets your kill streak & does not award you any experience for the kills you have obtained towards a kill streak

Must gain 2 or more with the Hidden Blade: Kills without being spotted, using anything other than the hidden blade WILL continue your streak but will not count towards the streak
Example: Getting 2 hidden blade kills then using a bow to kill the next enemy then another hidden blade kill, will only consist of 3 kill streak, since bow isn't a hidden blade but your streak still continues

Tested when being spotted with a yellow bar, instantly paused the game waited 3 minutes exactly & unpaused, I was awarded my experience before being spotted afterwards

If you're in a hidden location & the enemy you're assassinating responds to your attempt with a red indicator it becomes null indicator, your streak WILL remain in tact
Note: Assassination Chain Kill has a flaw, it will nullify your streak if spotted by the second enemy right as you use it, if the red indicator shows up

Be Warned: If you're on a ship even a large one with no enemies on board, during testing I was hidden but a crocodile spotted me even though I wasn't in sight for them to see, take care of your surroundings if you risk waiting it out

There is no Limit: At first the first few kills are inevitably small in terms of experience outcomes but the more you get, the more you are rewarded, see below for experience reference

Larger sum of bonuses given on 6th & 11th kill streaks only

Increased Bonus XP: rewarded on 6th & 11th kill streaks

• 1-5 kills 15xp each
  
• 6th becomes 120 & the increments become 20xp each
  
• 11th kill which becomes 330xp after which all experience gained afterwards is a max of 30 each kill for the streak
  
• Example: If you got a 30 kill streak you'll end up with 900xp gained 19 kills x 30 = 570 + 330 from 11th = 900xp

This was created because many people on different forums, Steam & Ubisoft alike, no one bothered testing it & just kept asking, so I have saved the entire gaming community the trouble, but I also enjoyed the game enough to do so, so I at least had fun

Good Luck & Have Fun