Ok first I'm probably sure that the reset is caused since custom DC field is designed numeric. what I want to use is a macro value instead: [[8+@{Rahxiros|PB}+@{Rahxiros|strength_mod}]] so basically yes I have a character with spellcasting ability and spell saves come from STR. Basicly this is what happens: I chose custom DC and put [[8+@{Rahxiros|PB}+@{Rahxiros|strength_mod}]] or 8+@{Rahxiros|PB}+@{Rahxiros|strength_mod} (without brackets) and when i close and reopen the window the value is reset to 0 as it should. I'm not a paid member so is there a possible way for me to do this as non static STR DC on the spellbook. the only other way I can think of is to put the DC as inline to description or somewhere there but if it's possible I don't want to add this as in line to every spell save description. little screenshots about the issue: goes back to this: