question

The PlayFab integration with Photon Cloud allows you to use our authentication call (to get a token for their service) and to use webhook calls from Photon Realtime to call into Cloud Script handlers hosted in PlayFab. Nothing about our integration blocks any of the functionality of Photon, but you can quite easily design your use of our services such that without a valid login from a purchased copy of your game, players cannot access the gameplay.

The way to do this would be:

• Generate coupons for your game which grant the user an item from your PlayFab-defined catalog. That item is then your "entitlement" to the player, for access to the game. Distribute coupon codes as part of fulfillment of a purchase of your game.
• When the player signs into PlayFab, check that they have the entitlement item. If they don't, prompt them to enter their code.
• Store data required by the title for gameplay in Title Internal Data, and have the client query for it via Cloud Script. The Cloud Script checks that they have the entitlement item and returns the data if they do.
• Since a hacker could bypass that by taking a legitimate copy of the game and recording the data, have that data be something that changes periodically if possible. Also, have there be server authoritative logic that's part of the game flow (in Cloud Script or if you're using Photon Enterprise, in that logic), so that there's a check for their entitlement occasionally (no more than every couple of minutes, though).