Contracts that depend on block timestamps for critical operations are susceptible to manipulation, as miners can slightly adjust the timestamps.
This can lead to unfair advantages in games, easier puzzle solutions, and flawed randomness, all of which an attacker can exploit.
block.timestamp or now for crucial contract functionalities.block.number for time-keeping if needed, as it is harder to manipulate.In a betting smart contract, if the outcome depends on a timestamp (like an even or odd timestamp deciding the winner), a miner could potentially manipulate the timestamp to affect the result.