Furnace of Rath and Heartless Hidetsugu?

[kartiv]

Do all players die if I use the ability of Heartless Hidetsugu with a Furnace of Rath in play?

[Arix]

Everyone with an even life total, yes. Everyone with and odd life total will be left at 1.

[Jiki]

I'm not a math expert, but if one card says they will lose "half" their life and the other card says to "double" it, wouldn't EVERY PLAYER die?

[Arix]

Hidetsugu doesn't say half though. It says half, rounded down. If your life total is 7, then half that is 3.5. Rounded down, that's 3. Doubled, that's 6. So you take 6 damage and go to 1.