In Draft, Attacked with Lightning, Army of One and 2 Gaelcats. Lightning hit opponent for one after blocks, when the Gaelcats hit opponent unblocked they dealt two each as expected after doubling. Then I cast Fire Magic tiered to deal 2 each. This was doubled to kill two of my opponents */2 and a */4 creature. But it also killed my Gaelcats which have 3 toughness. My lightning did survive. It had 3 toughness but also an indestructable shield from Zack Fair from earlier in the turn. I expected my Gaelcats to survive as the Lighning doubling is only supposed to be on the opponent that received damage and permanents they control.

Platform: Mac