Somatic Components

If an ability requires Somatic components then it requires the ability to gesture freely with at least one arm to be able to effectively use the ability. The GM has a certain amount of leeway in determining whether or not a certain situation precludes the use of somatic components, but if your hands are full or occupied (e.g. swimming), you are bound, or you are unable to move due to paralysis or a drained ability score, you cannot use these abilities. Grappling or being pinned usually also prevents the use of abilities with a somatic component, though the GM may rule otherwise in some cases.