Arts IF you can afford it.
H10, about a mile away ...if not.
Keep your wits about you both inside and outside casino and DON`T go flashing any wins around at the casino bars etc.
Take a taxi home late at night or walk back with a couple of friends.
Most muggers operate in gangs of 2-4 and generaly target single individuals or couples so always beware.
Barcelona is safe if you stay vigilant... but you need to take care.