Yes, 100%.
So unless you have a player who absolutely wants to rule-law you because "It is not forbidden by the rule", that should be enough.
If you want something supported by rule, any activity can be considered as tiring after a while.
I don't practice archery anymore, but I can tell you that after shooting 50 arrows, you are not as fresh as you were when you started. It does not take much strength, but concentration. If you are well trained, you can endure much longer I am sure, yet as innocuous as it seems it takes some resources. So it would be reasonable that for any activity requiring some modicum of concentration, you take a Fatigue level per hour of activity.
Otherwise, you strictly follow the rule: there are no rule to say that after trying X many hours, the magus will succeed without the player having to roll dice. So then, the only way to resolve the issue is to have the player rolls every f***ing dice. 360 dice for one hour...
I made some quick statistics :mrgreen: Assuming that he needs to achieve five 1s in a row, followed by any number giving a result between 64 and 320 (even more since he could still roll a one, but I wanted to keep the math simple)
He has a base chance of 0.1^5 per attempt, so 0.001 %, better than the lottery, yet...
Assuming one attempt per round (10s), that 360 attempts an hour, he has about 0.4% chance of success. (The math is the following: chance of not rolling 5 1s in 360 attempt: (1-0.1^5)^360, so chance of having at least 5 1s is 1-(1-0.1^5)^360).
If he keeps doing that for 10 hours, his chances increases to 3.5%.
Once he breaches the 100 hours mark (so 36'000 attempts), his chance will be 30.2% to have rolled 1 followed by another four 1s...
Since there is no rule preventing a magus to attempt that, but there is equally no rule to shorten the process that you can succeed by sheer dumb luck and persistence, the only way to solve this issue is to play it out...
I would say, with your friends, you decide one day to make this sacrifice and bite the bullet and to waste three hours of good gaming and you make him go through the process. I believe once should be enough to solve forever the issue.
By the way, that's how the companions and grogs of a magus trying to achieve a stupidly high score through only luck should feel: they are looking at an idiot who keeps repeating and repeating the same formula until something different happen than the one hundred times before. Only truly desperate person would ever try that.