Giggle

The following material is Open Game Content from a 3PP Source

GIGGLE
School enchantment (compulsion) [mind-affecting]; Level bard 0
Casting Time 1 standard action
Components V, S
Range close (25 ft. + 5 ft./2 levels)
Target one creature
Duration 1 round
Saving Throw Will negates; Spell Resistance yes

The target suddenly finds something humorous enough to start giggling, and the laughter lasts for one full round. While the target can still move and attack normally, he is unable to speak, or use bardic abilities or cast spells that rely on verbalization, until he stops giggling.