Rite of Ascension

From Memory Alpha, the free Star Trek reference

The Rite of Ascension is a ritual performed when a Klingon child who has reached the Age of Inclusion symbolically becomes a warrior. It must be followed by the Second Rite of Ascension in less than ten years in order for the Klingon to fully become a warrior. The rite involves the repeated use of painstiks to test the warrior's endurance and resolve. (TNG: "Firstborn")

Worf underwent his Second Rite of Ascension in 2365. (TNG: "The Icarus Factor")