[Magic help] concentration

Often, young characters will find themselves running into problems with
concentration.  Occasionally you may be told 'You can't concentrate enough.'
when attempting certain spells or skills. This is often because the feat that 
is being attempted is too difficult for the player to perform. All spells and 
some skills have a certain concentration requirement which must be met in 
order to be performed.

While concentration requirements for a certain spell or skill remain constant,
the total amount of concentration available depends on the character.  Smarter 
characters will have a great concentration allowance and can concentrate on 
more spells or skills at one time.  There will be times when a character has 
too many spells to maintain and cannot cast any more because of their limit.

Some things will affect the total concentration limit on a character aside
from maintaining spells.  Being involved in melee combat with other characters 
interferes with your concentration.  Being the target of skills like bash and 
trip will as well.  Resting or sleeping also decrease your total concentration
ability.  Two ways to increase your ability to concentrate include releasing 
spells and sitting before performing the feat.

See Also: release song dance