When rolling a toughness check I'm a little confused. An unmodified toughness roll goes against a damage dc of 15 in the chat, but if I add a modifier to it then it changes the modifier to the toughness roll AND the damage DC. So do we ignore the degrees of success or failure in the chat and figure it out ourselves or will there be a way to add what the toughness dc is or have modifiers not affect that the dc. I did a basic roll (+1 toughness), a +2 modified roll, and a +5 modified roll just to show what I mean in the picture.
Attachment 34959
I was trying to add the damage rank of a power as a negative modifier to the toughness roll to even out the DC 15 automatic adjustment but then it added to both the toughness roll and the DC