Can I assign a new capability when creating a role

So I a bit confused, because WordPress manual does not gives me an answer.

add_cap() function has the database storage call:

public function add_cap( $role, $cap, $grant = true ) {
		if ( ! isset( $this->roles[$role] ) )
			return;

		$this->roles[$role]['capabilities'][$cap] = $grant;
		if ( $this->use_db )
			update_option( $this->role_key, $this->roles );
	}

But what if I want to add new capability when creating new role. I.e. the new role should be ‘grandmaster‘ and I want to give him a new ‘can_play_chess‘ capability immediately in plugin activation:

$result = add_role(
    'grandmaster',
    __( 'Grandmaster' ),
    array(
        'read'         => true,  // true allows this capability
        'can_play_chess' => true,
    )
);

Is this is allowed, and is this is a correct way to adding both – new role and new capability.