This is a suggestion for a set of skills that would fall under a new skill tree. It would key off Lucky Charm. Skills would have a high degree of Risk/Reward outcomes. Most would be random probability with little to no skew to the player in any way unless highly invested in Lucky Charm. I would go so far as to suggest that any skills with random chance be 50/50 and only gain maybe an additional 2% per skill point in Lucky Charm skewed towards positive outcomes. (So at 1 point invested in Lucky Charm, a 50/50 shot now turns into a 52% chance at favorable outcome, 48% chance at unfavorable).

Skills would be highly volatile. Here's some examples.
(Gamble)All In: Spend your remaining AP to deal damage to an enemy. Every AP spent deals (X-Y) amount of damage. For every AP spent you have a 10% chance to remove an AP from the enemy's next turn. Melee Range.

Double or Nothing: At a 50% chance, Target enemy takes damage equal to the amount of damage he has taken since his last turn. If the skill fails, the enemy instead heals back the amount of damage he has taken since his last turn. (If that is too hard to program mechanics-wise, then change it to be equivalent to the amount of missing health the enemy has).

Roll the Dice: Roll a die and Gain a positive buff on yourself if you roll a 4, or 5. On a 6 gain 2 buffs instead. Rolling a 2, or 3 means nothing happens and rolling a 1 gain a debuff.

Russian Roulette: Select 2 Targets, they can be an ally or an enemy. One is randomly selected and takes (X-Y) Damage. The other Heals for (X-Y) Health.

The Price is Right: AP Cost 1. Heal for (X-Y) Health. At a 50% chance, this skill fails and instead of healing your turn immediately ends. Cooldown 0 or 1 Turn (should be really low.)

Everybody Wins!: Target an aoe. All characters in the aoe lose their buffs and debuffs. These are shuffled randomly amongst the targets inside the original area. Durations are not refreshed. Permanent buffs/debuffs cannot be shuffled.

Unstable Elements: Gain a buff for 3 turns. Upon being hit with elemental damage, have a 50% chance of healing that amount instead of taking damage. If it fails, you take double damage instead.

Trump Card: Cost is 1 Source point, 0 AP. Undo the effects of your last skill used this turn. AP spent on that skill is not refunded. Cooldown is not lifted from the skill you undid.

Playing with Fire: Req: 1 Lucky Charm, 1 Pyro. Set yourself and one target on fire. Every turn, burn damage on you and your target is doubled from the last turn. If the burn is removed on either person, the other's burn is removed too. (first to die loses).

Down the Drain: Req: 1 Lucky charm, 1 Hydro. Cost: 4 AP. Your turn ends. You forfeit your turn to ensure Target enemy forfeits their next turn. Any remaining AP on yourself or your target does not carry over to next turn.

Shoot the Breeze: Req: 1 Lucky charm, 1 Aero. Cost 1 AP. You and target enemy gain invisibility for 1 turn. Both characters gain a buff that leaves behind a smoke trail as they move.

Bet on Red: Req: 1 Lucky Charm, 1 War. Take Half your Maximum Health in damage. You gain a Physical Armor buff equivalent to the amount of damage you took for 3 turns.

So there's a bunch of ideas. I love gambling and randomness. If you make a class on it in the farrrrrr future, I'll be very happy! The skills are only ideas to fill in the theme of gambling. Vendor NPC in Fort Joy should be Griff or one of the 3 NPC's that cheat you at Cards. Thank you for reading!!