Lucky

Anyone can be lucky every once in a while, but not everyone can be Lucky consistently. It takes some skill. These lucky rogues tend to worship Gods of chance and luck, but are not devoted to any one god in particular. Like any fighter or ranger, a Lucky rogue may pray for his fortune or just head off to the local tavern to toss the dice. Few Lucky rogues have a real profession, they tend to live life on the edge.

Fortune's Favor

Starting at 3rd level when you choose this subclass, glimpses of fortunate outcomes begin to press in on your awareness. When you finish a long rest, roll two d20s and record the numbers rolled. You can replace any attack roll, saving throw, or ability check made by you or a creature that you can see with one of these foretelling rolls. You must choose to do so before the roll, and you can replace a roll in this way only once per turn.

Each favor roll can be used only once. When you finish a long rest, you lose any unused favor rolls.

Improved Critical

At 3rd level, your weapon attacks with a finesse or ranged weapons score a critical hit on a roll of 19 or 20.

Spread the Luck

Starting at 9th level, you learn how to gift a bit of your luck to others. You gain the ability to cast the guidance spell at will and the ability to cast the bless spell a number of times equal to your proficiency bonus per long rest. 

Stored Luck

Beginning at 13th level, once you roll a natural 20 (or critical hit from Improved Critical) you can choose to store the critical success for another roll, which forces you to reroll the current roll and take the new outcome. Until your next short or long rest you can replace any roll you make with this stored critical success. You can store a number of rolls equal to your proficiency modifier.

Master of Fate

Once you've reached 17th level you become a manipulator of fortune and fate, stealing fortune from others. Whenever a creature you can see rolls a natural 20, as a reaction you store the critical success as one of your Stored Luck and force them to reroll the current roll and take the new outcome.