Samwell Tarly survived the worst.
Samwell Tarly encounters the White Walkers during the ranging beyond the Wall in Season 2. However, he is not deliberately singled out or spared by the Night King or any White Walker.
The White Walkers operate with strategic indifference toward individual low-priority targets. Their focus is primarily on:
Expanding the army of the dead (wights),
Eliminating organized resistance when necessary,
Pursuing specific individuals of significance (such as Bran Stark, Jon Snow, and Daenerys Targaryen in later events).
Sam survives due to circumstance rather than intention: he is neither identified as a threat nor deemed strategically important, and he escapes amid the confusion of the encounter.
Therefore, his survival should be understood as incidental, not an act of mercy or selective restraint by the Night King.
Do you also think SAM was pardon?
A Weapon of Mass Distruction.
The Night King was created thousands of years before the events of the story by the Children of the Forest.
According to the show's lore:
During the war between the Children of the Forest and the First Men, the Children wanted a weapon to defend themselves.
They captured a man (likely a First Man). At a weirwood tree, one of the Children plunged a dragonglass (obsidian) dagger into his chest.
The magic transformed him into the first White Walker the Night King. This is shown in a vision witnessed by Bran Stark in Season 6.
The Night King exists only in the TV series. In the A Song of Ice and Fire books, there is no confirmed Night King character leading the White Walkers.
The books do mention a legendary figure called the Night's King, a former Lord Commander of the Night's Watch, but he is a different character from the show's Night King.
So, in the TV adaptation, the Night King was essentially a magical weapon created by the Children of the Forest that eventually turned against everyone and led the army of the dead.
They also became victim of their own creation.