Sand Tomb partially traps the target and deals 1/8 of the targets HP at the end of each turn. If a Binding Band is held by the user, the damage done at the end of each turn will increase from 1/8 of the target's maximum HP to 1/6. If the target uses Rapid Spin, it will be freed.
If a wild Pokémon uses Sand Tomb on the player's Pokémon, the player may escape if the affected Pokémon has Run Away or is holding a Smoke Ball. However, these do not allow the player to switch the Pokémon out.