Sometimes a dire situation will force a Wizard to go beyond the limits. A wizard may try to channel more arcane energy than their experience would allow.
When a wizard is low on spell energy or in extreme circumstances they may try to cast an additional spell or spells. They may cast any wizard spell, they have prepared, up to a level equal to their Wizard proficiency bonus. The Wizard must make a (DC8 + twice the spell level) Concentration check in order to cast the spell. If the check fails a magic mishap occurs (use the scroll mishap table, DMG, pg.140). If the check is successful the spell is cast normally. Either way the Wizard suffers exhaustion equal to the spell level, which means a spell cast at 6th level is guaranteed to kill the Wizard.
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