# Provably Fair

Provably Fair is an optional feature in DeBets that gives players the ability to verify the fairness of their bets. In order to understand how Provably Fair works in DeBets please refer to DeBets user documentation.

The support for Provably Fair introduces two requirements for your integration with DeBets:

• the outcome of every round must derive entirely from a seed that is returned by DeBets Seamless server on any debit request.
  Game servers generate outcomes using a PRNG (Pseudo-Random-Number-Generator) which is seeded using an internal mechanism. In order to support Provably Fair your game server must seed the PRNG using the external seed coming from DeBets Seamless Server, for every game round played on any of the games where Provably Fair has to be supported.

• in order to prove to the player that the mapping between seed and outcomes of the rounds that he played is correct and in order to let the player reproduce such outcomes you must provide DeBets with an API that allows launching the game in a special mode where game rounds can be played for free and where the outcome of any round that is played will be generated by the game server out of a seed whose value is specified as a parameter in the call of the API. DeBets Client App will then use this API to let the player verify that launching the game with a seed that matches the seed in the game round will reproduce the same outcome, while providing any other value for the seed will yield to different outcomes

The first requirement can be easily satisfied by seeding the PRNG with the seed received from DeBets Seamless Server and then extracting from the PRNG sequencially (without discarding any number and without ever re-seeding it) any random number required to generate the full outcome of the round.

The second requirement can be fulfilled by providing an API that launches the game in play-for-free mode and takes the following parameters:

• ID of the game
• ID of the gaming account
• player address
• seed

The implementation of the API will then take the seed and use it to seed the PRNG for any round played within that session.

# Enabling Provably Fair

The way you enable Provably Fair in your games depends on the way that you are using DeBets:

• If you are a game provider that is listing its games in DeBets website then you need to enable Provably Fair on any game where you want to support it (see Games configuration). The number of games that support Provably Fair will have an impact on your score which is shown in DeBets website.

• If you are using DeBets as a payment solution for your gambling website then you can control how to enable Provably Fair for any game that is launched.

When Provably Fair is enabled in the running game session the Client App shows the following:

Players can then verify the outcome of any round that they have played directly from the Client App.