Gambler

A young grinning man lays out his hand of cards, his voice like whiskey, mellow but backed with fire, "Four Emperors. I think thats my pot gentlemen. Lady luck is smilling on me today."  Right as his original hand of dwarves and dragons tumbles out of his sleeve and all hell breaks loose.

A wizend old gnome takes aim with his crossbow, talking to his companionsseated on the cart beside him. "Ayll bet ya ai caen shewt tha fancy haat uff tha there dwarves herd, tha wun ridun wit tham souldiors." His shot goes wide, richochets off a shield hanging from a warriors back, shoots straight up into the air, the sound catching everyones attention. With rapturous awe, everyone in the cart watches as the bolt comes down from the sky, through the dwarven mans hat, and into the backside of his horse. "TEWLD YA I CALD DU EET", AYM ON A STREK" the old gnome whoops and all hell breaks loose.

The assassin watches, unseen, from the balcony at the maelstrom of blades in the castle courtyard below. He knew that when all hell broke loose, that was his que, and lady luck was smiling on him today. He picked the lock on the window into his targets bedroom, sliding in unseen. He made a prayer to lady luck, betting his life on the lords faithful hound not hearing the sound of the window openning. The dogs ears barely twitched as he silently slid through the window. His knife finding clean and easy purchase in the lords back as his hand stiffled the cry. One attack was all it took, and the assassin fled into the night.

Gamblers take many forms, some find themselves in taverns and casinos around the continent. Others place their wagers on lifes simple things. But one thing remains true for all, when lady luck is smilling down on them, there is no more deadly enemy. Some gamblers live life on the edge, taking their luck as it comes. Others hone their craft and learn to read the signs so deftly, that they make their own luck.

 

Hustler

When you take this subclass at 3rd level, you know most games, and how to cheat them. You gain proficiency in all games, as well as in Charisma (Deception) checks and Dexterity (Sleight of Hand) checks, if you don't already have them. When making an ability check to cheat at a game, you have advantage on the roll.

Lady Lucks Fickle Favor

Starting at 3rd level, lady luck twists the world around you, but not always in your favour. Whenever you make an attack roll, saving throw, or ability check, a roll of a natural 1 always fails and a natural 20 always succeeds, irrespective of modifiers.

When you finish a long rest, roll a d20 and record the result. If the die shows a number between 2-10, you always fail on a roll of a 1 and the rolled number. If the die shows a number between 11-19, you always succeed on a roll of a 20 and the number rolled. This does not effect critical hits.

Making a Wager

When you choose this archetype at 3rd level, you begin to wager on outcomes in the universe, and lady luck hears you.

You place a bet on the likelihood of something happening. Whenever a creature you can see (inlcuding yourself) makes an attack roll, saving throw, or ability check, you may a number of times per long rest equal to your proficiency bonus, place a bet on the outcome. You may bet that the creature will succeed or fail on the roll. You must place a bet before any dice are rolled.

You may bet a number of d8's up to your proficiency bonus, minimum of 1d8. If the wager succeeds you gain the number of d8's bet as psychic damage on your next successful attack, if you bet on you own attack roll, you may add the damage to this attack. If the wager fails, you take psychic damage equal to the number of d8's bet. Self inflicted damge from this ability cannot be mitigated in any way. The results of the bet are determined when the DM declares the success or failure of the roll. Any effect that allows a failure to be rerolled does not change the outcome of the bet. 

Play the Odds

Starting at 9th level, you have learnt to twist luck every so often in your favor, and maybe bring some luck to another... good or bad... it depends, play the odds.

When you roll for Lady Luck's Fickle Favor you may roll 2d20's, and record both. You may pick one for yourself, and as a bonus action, give the other to another creature of your choosing. For 1 minute, the creature is affected by Lady Luck's Fickle Favor as if they were you, using the number you granted them. You may use this effect once per long rest.

Streak of Luck

By 13th level, you can snowball your luck. Not always for the best, but all bad streaks break eventually, and usually with a big break!

Steak of Good Luck. Whenever you suceed on two or more attack rolls, saving throws, or ability checks, in a row you become affected by the Bless spell until you fail on an attack roll, saving throw, or ability check. 
Streak of Bad Luck. Whenever you fail on two or more attack rolls, saving throws, or ability checks, in a row you become affected by the Bane spell until you succeed on an attack roll, saving throw, or ability check. 
Breaking a Bad Streak. Whenever you successfully hit with an attack roll while on a Streak of Bad Luck, that attack is guaranteed to be a critical hit.

Back a Winner

When you reach 17th level, you have become adept at picking the best places to make your gamble. Once per short rest, you may check the odds of success or failure on an action. When presented with an ability check or saving throw you can as a reaction make an Intelligence or Wisdom Check (determined by your DM) against a DC 15. If you succeed on this check the DM must tell you the DC needed to succeed on the check or saving throw. 

Additionally, whenever you make a wager on an outcome the creature who's rolling the attack roll, saving throw, or ability check you may choose for the creature to do so at advantage or at disadvantage.