Hardcover Textbook

Hardcover Textbook is a Relic in Wizard of Legend

Description
Increases the maximum number agents that can be active at once for all summon arcana by 1.

There is a hidden mechanic that limits the amount of agents that can be active at once for each summon arcana. By default the limit is 3 and Hardcover Textbook increases it to 4.

This is not to be confused with the effects of.

Strategies
This relic benefits builds that are limited by max cap for agents. Such as those that use and  or builds that have a high amount of cooldown reduction.

Additional notes

 * This relic only has a significant effect on agent summon arcana. It has no effect on seekers as their cooldown begins when all seekers are destroyed. Wards don't appear to have a limit to how many can be active at once.
 * Hardcover Textbook previously increased the maximum health of summon arcana before it was changed to the current version in the Thundering Keep Update.
 * The changes listed for Hardcover Textbook on the official website appear to be inaccurate for the changes the relic received in the 2nd Anniversary Update.