I know, I know, it's a bit presumptuous to start throwing around House Rules before I even have the dang book. But that's never stopped me before. 
Any math people or people some experience so far or anything care to comment on the possible following house rule?
Instead of having the Massive Damage save be a flat Fort DC15, I was considering having it be at "Damage Dealt". Ergo, you're hit for 23 points damage, it's a Fort(23).
This is a ton more lethal for the big damage. It's going to hurt the players (and anyone the players attack) more than it'll help anyone -- I could only see a few cases where a low-Con person is hit for 12 points damage and only has to make a Fort DC12 instead of 15.
Thoughts? Too killer? Game-Breaker? I don't have a game starting yet, so really, this is not an "I'm going to kill the players next week with this rule" kind of scenario. I'm just kicking around possibilities.
-Tacky

Any math people or people some experience so far or anything care to comment on the possible following house rule?
Instead of having the Massive Damage save be a flat Fort DC15, I was considering having it be at "Damage Dealt". Ergo, you're hit for 23 points damage, it's a Fort(23).
This is a ton more lethal for the big damage. It's going to hurt the players (and anyone the players attack) more than it'll help anyone -- I could only see a few cases where a low-Con person is hit for 12 points damage and only has to make a Fort DC12 instead of 15.
Thoughts? Too killer? Game-Breaker? I don't have a game starting yet, so really, this is not an "I'm going to kill the players next week with this rule" kind of scenario. I'm just kicking around possibilities.
-Tacky