Artifacts have 5 benefits associated with them. These benefits are represented by stars. Each benefit needs to be unlocked in order for it to become active when the Artifact is put on display in your Museum. When you craft an Artifact, it will start with 1 star or in rare cases 2 stars. That means your Artifact only has 1 or 2 of its benefits unlocked. Unlocking the other benefits can be done by collecting enough Supplies, Researchers, and Benefactors and using them for Unlock. Artifacts that are being Unlocked can’t be put on display in your Museum and the Unlock process takes time. After your Artifact has been Unlocked, it will gain a star and the corresponding benefit will be unlocked.
In battle, if your active benefits are significantly larger than your opponent’s then the maximum applied benefit will not exceed 85%. This also applies to when you defend against your opponent’s attacks.