What is the ruling on frequent wet dreams during the Night Vigil Prayer (Salat Al-Qiyam), and do they affect the validity of the prayer and the fasting?

If semen is discharged without desire, then ghusl (ritual bath) is not obligatory according to the majority of scholars; rather, only wudu (ablution) is required.

They based their argument on the hadith: "If the water gushes forth, then perform ghusl." The term "gushes forth" implies its emission with force and desire.

However, if you perform ghusl as a precaution, it is better, as it removes any difference of opinion. This seminal discharge does not affect the validity of your fast because it occurred involuntarily.