Overchanneling

You are attempting to either channel at a spell level over than what you are capable of channel or you have exhausted your spell slots, but still desire to channel.  Roll a d20.  You must beat a DC of the 10+ the attempted spell level.

If you fail this check, you must make a Fortitude Saving Throw.  Roll a d20 and add the modifier for your spell class (Sorcerer is Charisma, Wizard is Intelligence, etc.  This is a straight skill modifier, not your spell casting modifier). Subtract the level of the spell you attempted to cast from your saving throw.   The consequence of your overchanneling is listed in the below table.

20+. The channeler suffers a severe headache and overwhelming fatigue resulting in a -1 penalty on all skill and ability checks, attack rolls, and saves.  They are able to recover when they are able to rest for at least six hours.

16-19 The channeler suffers a severe headache and overwhelming fatigue resulting in  a -2 penalty on all skill and ability checks, attack rolls, and saves.  The take 1d6 damage and cannot overchannel until they recover. They are able to recover when they are able to rest for at least six hours.

11-15 The channeler suffers a severe headache and overwhelming fatigue resulting in a -3 penalty on all skill and ability checks, attack rolls, and saves.  The take 2d6 damage and cannot overchannel until they recover. They are able to recover when they are able to rest for at least 24 hours.

6-10 The channeler suffers a severe headache and overwhelming fatigue resulting in a -4 penalty on all skill and ability checks, attack rolls, and saves.  The take 3d6 damage and cannot overchannel until they recover. They are able to recover when they are able to rest for at least 48 hours.

1-5 The channeler suffers a severe headache and overwhelming fatigue resulting in a -5 penalty on all skill and ability checks, attack rolls, and saves.  The take 4d6 damage and cannot channel at all until they recover. They are able to recover when they are able to rest for at least two weeks.

<0 The channeler is stilled; completely unable to channel.  In addition, they suffer headaches and fatigue resulting in a -6 penalty on all rolls and takes 4d6 points of damage.