Fortuna

Fortuna is a being who personifies the concept of fortune itself, known as simply as The Lady of Luck. She travels through the Astral Plane on a great wheel, observing every possible outcome of every action. She is fickle and inscrutable, as quick to give her blessing as she is to take it away, and if trifled with she may even cast a curse that lays ruin on whoever fails at tempting her, she does however look favorably upon those who know how to play the odds, and if not squandered, her favor ensures that anyone can thrive should they know how to use it.

Expanded spell list
The Lady of Luck let's you choose from an expanded list of spells when you learn a warlock spell. The following spells are added to the warlock spell list for you.

Stacking the Deck
At 1st level your patron teaches you how to improve the odds in your favor, you gain proficiency with Dexterity (Sleight of hand) checks, as well as a special set of playing cards known as a gambit. You can summon your gambit to your hand as a bonus action, and you can use it as a focus for your warlock spells. Your gambit has a number of charges equal to your Charisma modifier, and you can spend them to produce the following effects. You can use these effects after you see the roll, but before any of it's effects are applied. You regain all charges of your gambit once you finish a long rest, and you get 1 additional charge whenever you roll a d20 and the result is either a 1 or a 20.
 * Whenever you or an ally that you can see makes an ability check, or saving throw, you can use your reaction and spend 2 charges of your gambit to grant them advantage on that check.
 * Whenever you or an ally that you can see within 30 feet of you makes an attack roll, you can use your reaction and spend 2 charges of your gambit to give you or that ally advantage on the attack roll.
 * Whenever a hostile creature makes an attack roll against you or an ally that you can see within 30 feet of you, you can use your reaction and spend 2 charges of your gambit to give that creature disadvantage on the roll.

Luck on Your Side
Starting at 6th level the laws of probability slightly shift around you. Within 10 foot aura centered around you the first attack roll, saving throw, or ability check that you, or an ally makes with disadvantage is made as a straight roll instead; and the first attack roll, saving throw, or ability check made by a hostile creature with advantage is also treated as a straight roll. You can only grant this benefits once per round. At 12th level the range of this aura becomes 15 feet.

Reversal of Fate
Beginning at 10th level you gain the power to subvert the fortunes. When initiative is rolled you regain 1 charge of your gambit. Additionally whenever you or a creature that you can see makes an attack roll, saving throw, or ability check, and rolls either a 1 or a 20, you can use your reaction to treat that roll of a 20 as a 1, or make the roll of a 1 be treated as rolling a 20. You can use this feature twice, and you regain all uses when you finish a short or long rest.

Double or Nothing
At 14th level you can drastically alter the fortunes of everyone around you. Whenever you or a creature that you can see makes an attack roll, damage roll, saving throw, or ability check, you can use your reaction to apply the following results based on the result of the roll of a single d20 called a  Coin toss, this type of roll negates both advantage and disadvantage for it. You can use this feature after the roll is made, but before any of the results are applied. You can use this feature twice, and you regain all uses once you finish a long rest.
 * 11 - 20 : The result of the roll is treated as having rolled the highest possible amount.
 * 1 - 10 : The result of the roll is treated as 1.

= Eldritch invocations =

The Edge of Fate
Prerequisite: The Lady Luck Patron, Pact of the Blade feature

You can use your gambit as your pact weapon, it deals slashing damage equal to 1d6 + 1 + your Dexterity modifier, it has the thrown (80/320) and finesse properties, you can make up to 4 ranged attacks with it before you must summon it back. Additionally you learn the  True Strike  cantrip if you don't already know it, and you can cast it as a bonus action without the need for concentration a number of times equal to your Charisma modifier, and you regain all uses once you finish a long rest.

Text of the Prophets
Prerequisite: The Lady Luck Patron, Pact of the Tome feature

You can use your gambit as your book of shadows. Additionally you learn the  Blade Ward  cantrip if you don't already know it, and you can cast it as a reaction a number of times equal to your Charisma modifier, and you regain all uses once you finish a long rest.

The Fated Friends
Prerequisite: The Lady Luck Patron, Pact of the Chain feature

You learn the  Guidance  cantrip if you don't already know it, you can cast it as a reaction, and all allies within 5 feet of your familiar gain the benefits of the spell for it's duration, you can cast it in this way a number of times equal to your Charisma modifier and you regain all uses once you finish a longe rest.

Coin of the Boatman
Prerequisite: The lady Luck Patron, Pact of the Coin feature

You can use the coin granted by your patron as your gambit, instead of the regular playing cards, as a bonus action you can channel the power of your patron through it, apply one of the following result based on the result of a  Coin toss. Once you use this feature you can't use it again until you finish a long rest.
 * 11 - 20 : You gain 2 charges of your gambit
 * 1 - 10 : You lose 2 charges of your gambit

Fortune of the Gambler
Prerequisite: The Lady Luck Patron, 5th level

Any feature that would give you charges of your gambit restores twice the normal amount, but if you have no charges of your gambit left you suffer the following penalties for 1 minute.
 * You have disadvantage in all ability checks.
 * The first melee attack roll a creature makes against you is done with advantage.
 * Enemies have advantage against your spell saving throws.

Lucky Shot
Prerequisite. The Lady Luck Patron, Pact of the Blade, 5th level

The range on your gambit's ranged attacks is now 150/600. Additionally your ranged attacks with your gambit score a critical hit on a roll of 19 or 20.

Mastery of Probability
Prerequisite: The Lady Luck Patron, Pact of the Coin, 15th level

Whenever a feature would require you to make a  Coin toss  to determine an effect, you can choose which result to take regardless of th actual result of the roll. Once you use this feature you can't use it again until you finish a long rest.