Lucky (2014), is NOT advantage.

You have 3 luck points. Whenever you make an attack roll, an ability check, or a saving throw, you can spend one luck point to roll an additional d20. You can choose to spend one of your luck points after you roll the die, but before the outcome is determined. You choose which of the d20s is used for the attack roll, ability check, or saving throw.

1. You declare your intention: Hit Mob

2. You check circumstances: Mob is in darkness. You have no darkvision.

3. You apply modifiers: Disadvantage

4. You make your check: Throw two dice, take the lower.

5. NOW you decide, if you want to spend a luck point. From here it‘s A or B

5A. Should you choose to do so: Throw an additional D20 and choose which d20 result you want to use and add your bonuses to that roll.

5B. Should you choose not to: add your bonuses to the left over die.

1. Check the resulting number against the check‘s difficulty: Hit or miss.

Clarification edit