Even if the Pokémon with this Ability is Ghost-type or holds a Shed Shell or Smoke Ball, it cannot be forced to switch or flee. If a Pokémon with this Ability is under the effect of Ingrain, Suction Cups will take priority over Ingrain if it would be forced to switch or flee.
If a Pokémon with Suction Cups hits a Pokémon holding a Red Card, the Red Card will still activate and be consumed, but fails to cause that Pokémon to switch out or flee.
Outside of battle
This move effect may be in need of research. Reason:In Generation VII, does Suction Cups only make Pokémon fishing encounters more common, or does it make hooking anything more common? You can discuss this on the talk page.