A question for the hive mind!

Are there any tips on how to handle "luck / fortune" roll mechanics, in games where a player can influence the outcome of a die, but must declare doing so before the die is rolled.
Such as where a player can have their PC do things like:
• roll a d20, and then choose whether the attack uses the attacker’s roll or yours
• replace any attack roll, saving throw, or ability check made by you or another creature

Because waiting for the player to say they will use or not use this cannot work (slows the game down way too much).

I have some ideas of how to adapt this:
• for example letting the player use their power after the roll is made (which is a big boost since they know what the outcome of the roll is before switching it) but subjecting this to Fate: having a 50/50 chance that it works (to balance the added power).

My question is: has this been discussed somewhere? Are there PnB rules that work for this?

This is super easy.

There's a free text field called "Reason for roll" on the dice roller. Simply require that players put in a note with this declaration in this field, and if necessary specify what the default behavior if they don't make any such declaration.

This is the equivalent of declaring before the roll.

This.

While I haven't used the field for exactly what your specifying it is a great place to prove that you decided to do something before actually rolling. In my preferred system you can spend a point of Willpower to improve the roll. When I'm GMing I will only accept the Willpower usage if the player notes it with their roll.

Thanks a lot!

Not at all what I was asking, but that is fine.

This message was deleted by the user at 22:24, Thu 15 Sept 2022.