You can nest abilities and use math, but it wont work everywhere. You also have to use the full @{character name|Attribute} syntax to nest abilities. What I mean by it wont work everywhere is, if you have an attribute set to (@{character name|Attribute1} + @{character name|Attribute2}) and you try to set one of the bubbles to that attribute, it will just include the text instead of the value that the calculation would give. you will get errors like that in a few other places if i remember correctly, so I would recommend waiting till character sheets come out if you need to do a lot of stuff along those lines. Oh, another big issue with the nesting, if you need to have a bunch of sheets with the same kind of setup, you need to go into each one and change the character name inside each attribute call to the right name for the sheet. duplicating a template sheet becomes less useful when you still need to edit quite a few major items that way to not screw yourself up.