Formula in Attributes?

Hey, I'm a bit new to roll20, so I'm not really familiar with all the doodads just yet. But, I run a game where the PCs can accrue 'Fatigue', which drops their maximum HP by the Fatigue's rating. So if you have 45 max HP, and you get Fatigue 10, then your Max HP is 35. I've just been having the PCs edit their Max HP attributes directly, but it can be a pain sometimes. Is there a way to set it up so your Max HP is a function of your 'maximum HP - Fatigue' or something like that?

As long as it's just math, and doesn't required any logic, then you should be able to do it.

You won't be able to do it automatically, as Macro's can't change values, unfortunately. IF you want to upgrade your membership to Mentor level, you'll get access to the API and you can pretty much do anything you want. However there's a couple ways you can make it slightly easier to manipulate than having to open the character sheet. On your character's token you have three bars. If the token is linked to their Character Journal sheet, you can link one of those bars to HP attribute. Whenever you take Fatigue, you can directly edit the token bar and it will effect the sheet. If you store the HP Attribute in the sheet with current/max values both filled in, it will give you a visual bar as well. Alternatively, if it only comes up occasionally, you can just have a Fatigue attribute linked to your token and use a macro to subtract that value from your MaxHP Attribute in your sheet and display it in the chat window. @{CharacterSheetName|AttributeName} or @{Selected|AttributeName}

Couldn't you just have an HP attribute and a Fatigue attribute and put something like this in the HP attributes: (45-@{Fatigue}) or [[(45-@{Fatigue})]] As Mark is saying, you could could also link your HP and Fatigue attributes to one of the token circle/bar to save time. If they are already used I suggest telling your PC to open their attribute and abilities tabs, put attributes that they want to change often on top and double click on the top of the character sheet to minimize it. (my players do this and move the now minimize sheet at the bottom of the screen, it's also transparent so it doesn't clutter the screen) Hope it helps!