function startRound() private
    {
        require(games[round].ended == true);

        uint256 crystalsLastRound = games[round].crystals;
        uint256 prizePoolLastRound= games[round].prizePool; 

        round = round + 1;

        uint256 startTime = now;

        if (miningWarDeadline < SafeMath.add(startTime, MIN_TIME_WITH_DEADLINE)) startTime = miningWarDeadline;

        uint256 endTime = startTime + HALF_TIME;
        
        uint256 engineerPrizePool = getEngineerPrizePool();
        
        uint256 prizePool = SafeMath.div(SafeMath.mul(engineerPrizePool, 5),100);

        Engineer.claimPrizePool(address(this), prizePool);
        
        if (crystalsLastRound == 0) prizePool = SafeMath.add(prizePool, prizePoolLastRound);

        games[round] = Game(round, 0, prizePool, startTime, endTime, false);
    }