Last Man Standing

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- Normally, fee calculations should be as precise as possible to avoid loss of funds due to rounding errors.

- The current implementation uses integer division for percentage calculations, which can lead to precision loss, especially for small values.

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// Root cause in the codebase with @> marks to highlight the relevant section

function claimThrone() external payable gameNotEnded nonReentrant {

@> currentPlatformFee = (sentAmount * platformFeePercentage) / 100;

@> claimFee = claimFee + (claimFee * feeIncreasePercentage) / 100;

}

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**Likelihood**:

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- This will occur on every claim, especially when claim fees are small or percentages are not multiples of 10.

- The effect is more pronounced as the game progresses and claim fees increase.

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**Impact**:

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- Small amounts of ETH may be lost due to rounding down, reducing the pot and platform fees over time.

- Players and the platform owner may receive less than expected.

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Here are some loss scenario's.

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// No loss scenario

sentAmount = 0.1 ETH = 100000000000000000 wei

platformFee = (100000000000000000 * 5) / 100 = 5000000000000000 wei

// Perfect division - no loss!

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// Negligible Loss

sentAmount = 100000000000000001 wei (0.1 ETH + 1 wei)

platformFee = (100000000000000001 * 5) / 100 = 5000000000000000 wei

// Lost: 5 wei out of 0.1 ETH = negligible

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// Loss scenario

sentAmount = 999 wei

platformFee = (999 * 5) / 100 = 49 wei // Lost: 4995 - 4900 = 95 wei

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// Small amounts

sentAmount = 99 wei

platformFeePercentage = 5%

currentPlatformFee = (99 * 5) / 100 = 495 / 100 = 4 wei

// Lost: 495 - 400 = 95 wei (truncated)

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// Fee increases

claimFee = 133 wei

feeIncreasePercentage = 10%

increase = (133 * 10) / 100 = 1330 / 100 = 13 wei

// Lost: 1330 - 1300 = 30 wei (truncated)

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Consider using a higher-precision base (e.g., basis points or 1e4) for percentages, or document the rounding behavior clearly.

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- currentPlatformFee = (sentAmount * platformFeePercentage) / 100;

+ currentPlatformFee = (sentAmount * platformFeePercentage) / 10000; // if using basis points

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