Originally posted by Shaddar
The core says that ambition 3 terrestrial workings can do supernatural things if its limited to one subject or small room. What would be the power cap for that?
I been using it to create creatures with power comparable to a first circle demon and to grant "cheap immortality"(cant die but it keeps aging, you have to kill a virgin every month, cant go more than 3 miles from the sacred tree)
High-end Terrestrial Workings can be powerful, but are still subject to the normal limitations—that is, they mostly deal with "transforming, enhancing, or weakening pre-existing aspects of the natural world" and can only manifest truly magical power in a limited or specialized way, as opposed to the "miracles of outright supernatural power" that are Celestial Workings. It's up to the Storyteller and players to discuss where precisely they want to draw this line at their table.
As for your specific examples, I think you're undershooting them a little. Creating a totally new creature with the power of a First Circle Demon is probably an Ambition 1 Celestial Working, while even the most conditional of immortality is probably going to be Celestial and Ambition 2+.