I also have a player who wants to "stay committed" on his Enhance power, and neither of us was aware of the optional rule. I think he'll agree it's fair.

I don't think it's been specified yet, but for those who need to point it out, it's described in the box on p.282 of the Force & Destiny Core book: "Committing Force Dice Over Multiple Encounters."

On the subject of re-rolling until success, you have a bit of flexibility. In general, a Skill Check already represents your best effort, so whatever amount of time you spend on a task, you roll the dice at the end of that period. Taking things slow may add boosts to the roll if it makes sense.

I'll allow a re-try if something changes the situation. For example, if the players fail to unlock a door, that door remains closed. But, if they find a code-cylinder that has authorization for that door, the situation (and difficulty) has changed and they can make another attempt.

Also remember that you can alter what "Failure" looks like. If the door not opening would stall the adventure, then it needs to open regardless. If you don't have another way in, then maybe a failed computer check only unlocks the door without activating the servos that open it, so it needs to be opened manually (Athletics) while a patrol of troopers is closing on your position. Failure should create drama, not stop the action.

Another fallback, if players really enjoy try and try again, is the same narrative approach I use with "looting." The rest of the galaxy is not static, waiting for you to walk in and trigger the action. If you spend days flying planet to planet, not only are you incurring docking fees and fueling costs each time, you also are letting missions go by, bad guys get away, the Empire gets stronger, etc.

"When you fail, you try again."

There is no problem with that. Imagine you are in combat, your players miss their first attack and you stop allowing them to shoot again. ;-)

At the same time failure means that your commited to something, invested into it and failed to achieve your desired result. You missed your shot, you were not able to repair that computer today, your whole day shopping trip downtown turned up with a bunch of useless stuff, a nice restaurant bill, but you did not find the right new shoes you wanted and try more stores next weekend, your car restoration project was not finished within the 6 months period as you planned, etc

You spend resources for each check, sometimes just time, sometimes time and money, sometimes even something irreplaceable. Either way, if you fail it does not mean you can not try again, but that the resources you spend are gone.

Getting back to that OP. We have here a force wielder who meditates each new day for some time, tries to activate a power, while staying calm and collected. Now if this power would need indeed a few force pips he might need sometimes a lot longer in the morning to get ready has he fails to achieve the state of mind (roll the light side pips) and get late to appointments or whatever based on that or needs to abandon his idea of activating this force power.

Naturally in committing dice is an automatically sucess, so in this case it cost him just the time for his morning ritual as he never fails with that. ;-)

And I stick to handing out conflict for that specific ritual, after thinking about it I would give 1-2 conflict per session for this behavior. That really is not much change for the roll, but it represents quite well this slight abuse of power.

"When you fail, you try again."

There is no problem with that. Imagine you are in combat, your players miss their first attack and you stop allowing them to shoot again. ;-)

At the same time failure means that your commited to something, invested into it and failed to achieve your desired result. You missed your shot, you were not able to repair that computer today, your whole day shopping trip downtown turned up with a bunch of useless stuff, a nice restaurant bill, but you did not find the right new shoes you wanted and try more stores next weekend, your car restoration project was not finished within the 6 months period as you planned, etc

You spend resources for each check, sometimes just time, sometimes time and money, sometimes even something irreplaceable. Either way, if you fail it does not mean you can not try again, but that the resources you spend are gone.

Good examples. We're basically discussing narrative vs. structured gameplay. Since it's a little off the original topic, I'm going to take it to a separate thread.

Short version, in combat, yes you can roll again, but first. ...

On the OP, as was already discussed, you don't roll for that particular enhance upgrade. You just commit a Force Die, and if he wants to keep it on, use the Sidebar rule that he doesn't recover strain.

For other powers, the question remains. Can a player keep rolling until success? I think the rules are open enough when it's a narrative attempt, and you can decide what works for you. My basic rule is that in narrative gameplay, you can check once per "scene" either the Force is with you or it isn't. The issue with using narrative time to keep rolling without cost or risk is that the dice become irrelevant. So, I think perhaps Conflict is a fair balance to that, but not automatically. Let the player roll their force dice once. If they don't get the pips they need or want, they can a) use the dark side pips as normal or risk conflict by rolling again. On any roll after the first, any force die that comes up 2D (two dark side pips) will give a point of conflict as frustration (anger) begins to take hold. If it's all single dark side faces, no effect. Once conflict has been gained in this way, if the risk increases. The next die roll that results in a 2D lets the Dark Side in fully. One light side destiny point is flipped to dark, and the character gains the force points from the roll, gaining conflict as normal.

edit: It seems no matter how many times I review before posting, some typos only show up after.