Berserkers of Blood Ridge attacks each turn if able what means this magic rulings faq

[lucky]

waht does it mean that Berserkers of Blood Ridge attacks each turn if able? Like if its untapped on opponents turn does it also attack then?

[Arix]

No, only the active player can declare attackers.

What it means is that, on your turn and during your declare attackers step, if it can attack, it has to. Does it have summoning sickness? Is it tapped? Is it under the effect of Pacifism or any similar effect? Does your opponent control something like Ghostly Prison? If the answer's "no" to all of those, then it attacks, whether you want it to or not.

[lucky]

what if the opponent controls ghastly prision but I have 2 mana available do I have to pay and attack?

[Arix]

It depends. Do you have 2 mana in your pool, right now? Or do you just have two untapped lands? If it's right there waiting in your mana pool, then yes, you'll have to pay and attack. If you just have two untapped lands though, then you don't. Although the Prison forces you to pay mana, it never forces you to actually draw that mana from your available sources.