Minecraft wiki entry for Guardian, associated text: The laser takes 2 seconds to charge, doing no damage in the meantime. It starts out purple and fades to yellow. Once charged, the laser flashes green and deals 6 regular damage and additional 1 magical damage on normal difficulty. The latter bypasses armor. Guardians swim around for 3 seconds before firing again. If the target approaches while the guardian is loading its laser, it stops firing and swims away until it is at a comfortable range, at which point it continues attacking. The laser cannot be dodged or blocked by a shield and has a maximum range of 15 blocks.