Reward book (Combat Academy) can no longer be obtained in RuneScape after an update but still exists in-game for those who had done so.

The reward book is a reward given to players who tested the Combat Academy. After finishing a section in the combat academy, the player can open the course interface and right-click on the rank and select Claim-Reward to claim the book. If all 21 sections were completed, 21 books will be given. They can also be claimed from Lady Deathknell.

The books can give experience in one of any of the following skills: Attack, Strength, Defence, Constitution, Ranged, Magic, Prayer, Herblore, Summoning, Slayer

The experience ${\displaystyle x}$ obtained at level ${\displaystyle l}$ is:

${\displaystyle x=l^{2}-2l+100}$
``` template  = Template:Combat Academy calc
form      = ccr
result    = reward
param     = level|Skill level|1|int|1-99
param     = books|Amount of books|1|int|1-21
```