You don't need an Action Replay to get one, no.
You could have got a "Member Card" from the WiFi Darkrai event (August 3rd - September 13th 2009), but that date has passed now. There may be another Darkrai even in months to come.
You can get one with an Action Reply, or with Pokésav, but the only other way to get one Legitimately now is to trade with someone for one.
The WiFi event at the moment is actually a Shaymin (for Platinum users).
Then you can't.
You can only get it by Action replay,Mystery gift or Wi-fi conettion
i think you might need to have a action replay
No, you need Action Replay
you can use action replay
One of the best ways to get Darkrai without using an Action Replay is by trading with a friend who has it. If they don't, wait for an official Pokemon event for Darkrai. The next one will be in May 1st for X, Y, Omega Ruby, and Alpha Sapphire.
you must have action replay to catch darkrai, it doesn't goes without.
um never without action replay
You cant you have to buy action replay
Sorry, you can't.
Use action replay.
get a darkrai from your friend[note if they want to trade)