The ability holder cannot be forced to switch out or flee by the opponent. This includes moves like Roar, Dragon Tail and Circle Throw as well as the item Red Card. The ability holder cannot be forced to switch or flee even if it is Ghost-type or holds a Smoke Ball or Shed Shell. Suction Cups does not prevent the Pokémon from using fleeing moves like Teleport or Baton Pass or items like Eject Button.
Outside of Battle
When the ability holder is first in the party, the chance of landing a Pokémon increases while fishing.