Book of Skill in Diablo II.
The Book of Skill is a Tome (item) that is a usable quest item in Act II of Diablo II.
How to Get
It can be obtained after defeating Radament for the first time, completing the Radament's Lair quest. Upon 'reading' the Book of Skill the player is rewarded with one Skill Point.
It only drops once per Difficulty.
References
- Diablo II gameplay