A player asked this in a local group and I'm not sure of the correct answer

ok i have power artifact , ghostfire blade and a 0/1 pest token in play are all the reductions in cost applied at once leaving the cost at one or can i apply them in an order to make it 0 mana to equip?

The player gets to choose the order to apply the effects. If you want to do things smart, you'll apply Power Artifact first, then the effect from the Blade to make the cost 0. If, for some reason, you want to apply the Blade first, then the cost is reduced to 1, then Power Artifact won't really do anything since it can't reduce the cost to below 1.

In short: you should apply Power Artifact first, then the Blade, to get the cost to equip to be 0.

Nathan Long
Wizards.Com Boards NetRep