Mages start game with 0 spell points and 0 spells in their spellbooks. At start of the planning phase each Mage gains 10 spell points (if Arena) or 5 spell points (if Academy) to purchase spells from the shared card pool. Each player takes turns purchasing 1 spell from the card pool at a time in order of reversed initiative, until all players have either passed or run out of spell points.
Everything else works the same as normal for Academy or Arena.