Loaded a 10 into the jewel. Then selected 5d20 from the 20-sided die. Results =
Attachment 55342 . That is how I handle NPC attacks (where you have to add the stat to the Expertise category for your TN). I then loaded a 10 into the jewel and rolled an Acrobatics check off a PC sheet. TN should have been 11 based on the stats but it instead added 10 to the TN to make the new target number 21. Results =
Attachment 55343 . I'd never done that off a PC sheet before though bc it usually just auto-calculates it (i.e. in this case the 11) and you don't add mods to PC rolls in general so I don't know what it did before.