Community

What are the limitations of using a permanent's ability to "play a card"? If I have a Mosswort Bridge that has hidden a Platinum Angel , can I use the ability on my opponent's turn? (Given that I have 10+ power on the board). Could I use the ability to play Platinum Angel in repsonse to losing from some cause? (Poison, damage, etc.)

You can use activated abilities anytime you could cast an instant unless the ability specifies otherwise.

When a one-shot spell or ability tells you to "play/cast a card" it lets you ignore all timing restrictions. In fact, most of these abilities let you cast a spell while an ability is in the middle of resolving, which is something that's normally impossible.

Comtinuous effects that let you play/cast a card (like Praetor's Grasp or Spelljack ) don't do this.

spells or abilities that allow you to cast a spell (without specifying a duration) allow you to cast that spell as that spell or ability is resolving

examples
activated ability on Djinn of Wishes
Brilliant Ultimatum spell
triggered ability on Wild Evocation

yes, you could activate Bridge any time that you have priority to cast Angel while the Bridge ability is resolving

other abilities or spells that specify a duration do not let you cast that spell as it is resolving rather they create an effect that gives you an additional location to cast it from, but it still has to follow normal timing rules for casting

examples
trigger on Intet, the Dreamer
flashback
static ability on Magus of the Future
Praetor's Grasp spell

Note that you can't respond to loosing the game. Platinum Angel needs to be in play before the thing that would cause you to loose happens.  

Okay. I understand the lack of timing restriction, but could I use the Mosswort Bridge ability to cast the Platinum Angel in response to an opponent casting a spell that would cause me to lose? If I was at 3 life and an opponent cast a Lightning Bolt , could I cast the Platinum Angel in response to the Bolt resolving?

Jan 3, 2013 -- 9:10PM, Tunklebunkle wrote:

Okay. I understand the lack of timing restriction, but could I use the Mosswort Bridge ability to cast the Platinum Angel in response to an opponent casting a spell that would cause me to lose? If I was at 3 life and an opponent cast a Lightning Bolt , could I cast the Platinum Angel in response to the Bolt resolving?

Yes.  The Angel will resolve first.  When the Bolt resolves you will be at 0 life, but you won't lose.
 

Jan 3, 2013 -- 9:10PM, Tunklebunkle wrote:

Okay. I understand the lack of timing restriction, but could I use the Mosswort Bridge ability to cast the Platinum Angel in response to an opponent casting a spell that would cause me to lose? If I was at 3 life and an opponent cast a Lightning Bolt , could I cast the Platinum Angel in response to the Bolt resolving?

Yes, it's a normal activated ability and follows the regular rules of activating activated abilities. The spell gets cast as the activated ability resolves, and will resolve in response to Lightning Bolt.