# Roulette

The `Roulette` smart contract is a part of a decentralized gaming platform, specifically designed to handle the logic and operations related to playing a game of roulette. It leverages the Ethereum blockchain for transparency, fairness, and security. The contract employs Chainlink's Verifiable Random Function (VRF) to ensure the randomness of roulette spins, integrates with a dynamic staking system, and adheres to the game interface standard defined within the platform.

## Key Features

* Implements [Chainlink VRF](https://vrf.chain.link/) for provably fair randomness.
* Integrates with a [Dynamic staking](/smartcontracts-description/dynamic-staking.md) mechanism for handling bets and payouts.
* Enforces betting limits and validates bet data.
* Non-reentrant to prevent re-entrancy attacks.
* Emits events for key actions: bet placement, spin result, etc.

### Variables

* `REQUIRED_FUNDS_COEFFICIENT`: Multiplier for validating sufficient balance.
* `subscriptionId`, `vrfCoordinator`, `keyHash`: Chainlink VRF configuration.
* `limits`: Struct mapping defining minimum and maximum bet sizes.
* `staking`, `core`: Addresses for the [staking](/smartcontracts-description/dynamic-staking.md) and [core](/smartcontracts-description/core.md) contracts.

## Functions

### Public and External

* `getPossibleWin`: Calculates the maximum possible win for given bet data.
* `placeBet`: Initiates a roulette spin request for a player. Validates bet data, requests randomness, and records the bet.
* `getAddress`, `getVersion`, `getFeeType`, `getStaking`: Interface implementations providing contract details.
* `setLimit`: Updates minimum and maximum bet sizes for a specific bet type.

### Events

* `Rolled`: Emitted when a roulette spin is requested.
* `Landed`: Emitted with the result of a roulette spin.
* `LimitChanged`: Emitted when bet limits are updated.


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