The immutability of smart contracts guarantees the fairness of the game, allowing users to participate with confidence. #### Decentralization: 
The decentralized nature of blockchain avoids the risks of a single centralized point, enhancing system security. #### User Experience: 
Telegram Bot provides a convenient interaction interface, lowering the participation threshold for users. #### Key Features:
Lottery Documentation: Detailed lottery rules, fairness, and transparency explanations. #### Single Bet: 
Users can place a single bet on a number. #### Combination Bets: 
Options like “Leopard” (three identical numbers), all odd, or all even. #### Range Bets: 
Betting on a range, e.g., 1-333. #### Sum Bets: 
Betting on the sum of the drawn numbers. #### Burn Amount: 
Tokens burned in the process. #### Staking Function: 
Allows users to stake tokens for dividends and additional lottery participation. # Overall Architecture: #### Backend:
Smart Contracts: Written in Solidity, deployed on Ethereum or other EVM-compatible blockchains, handling game rules, prize distribution, and random number generation. #### Node Services: 
Interact with smart contracts, providing APIs for the frontend to call, such as balance queries, betting, and retrieving results. #### Frontend:
Vue.js: Builds the user interface, providing user interaction functions including registration, login, betting, and queries. ![contract lottery game ](./img/lotto_buy_eng.jpg "contract lottery game in telegram")

Chainlink VRF: Provides secure on-chain random number generation services, ensuring the fairness of the results. #### Game Play and Solidity Code Example: 1. Smart Contract (Lottery.sol) ``` // SPDX-License-Identifier: MIT pragma solidity ^0.8.0;

function requestRandomWords() internal returns (bytes32 requestId) {
    // ... Call Chainlink VRF to get random numbers
}

function fulfillRandomWords(bytes32 requestId, uint256[] memory randomWords) internal override {
    // ... Determine the result based on random numbers
} } ``` 2. Game Play: #### Single Bet: 
Users select a number to bet on. #### Combination:
Leopard: Three identical numbers.
Odd/Even: Sum is odd or even.
Sum: Sum of three numbers.
Current Data Display: Real-time display of current betting status, prize pool amount, countdown to draw, etc.
Historical Results Display: Shows historical draw results, including winning numbers and winners.
Staking Dividends: Users can stake tokens in the smart contract to receive platform dividends.
Staking Lottery: Staked users have a chance to participate in a draw for 10% of the dividend as a grand prize. #### Frontend (Vue):
User Interface: Design a simple and beautiful user interface for easy operation.
Data Display: Real-time display of game data, such as prize pool amount and countdown to draw.
Interactive Functions: Implement user registration, login, betting, and query functions.
Backend Interaction: Use Axios or other HTTP client libraries to call backend APIs for data interaction. #### Chainlink VRF Integration:
Configuration: Configure the contract on Chainlink VRF, set request parameters, callback functions, etc.
Call: Call the requestRandomWords function in the contract to request random numbers.
Callback: Chainlink VRF will callback the generated random numbers to the contract’s fulfillRandomWords function. #### Security and Fairness:
On-Chain Random Numbers: Use Chainlink VRF to generate unpredictable random numbers, ensuring the fairness of the results. #### Smart Contract Audit: 
Conduct strict audits on smart contracts to discover and fix potential vulnerabilities. #### Multi-Signature: U
se multi-signature mechanisms for key operations to enhance security. #### KYC/AML: 
Conduct identity verification according to local laws and regulations.
By combining Telegram Bot, Vue.js, Solidity, and Chainlink VRF, we can build a secure, fair, and transparent blockchain-based lottery game. This solution not only ensures the fairness of the game but also provides an excellent user experience.