Some creatures have been given a '0' for certain characteristics which means they have no ability what-so-ever in that field! This usually applies to creatures unable to use missile weapons, so they have a BS of 0, but it might equally well apply to other characteristics too. For example, an ordinary horse has no Attacks (A 0). If a creature or object has a WS of 0 then it cannot defend itself in hand-to-hand combat, and any blows struck against it will automatically hit.