A useful mantra to bear in mind is "the client is in the hands of the enemy".
Any capability that you build into the client that can run offline is one that you have delivered in a gift-wrapped package to anyone who wishes to hack the game.
If the client is capable of producing a valid play history that passes muster for server inspection, then a ...
Based on my understanding it would be much harder for hackers to send fabricated message to the server and cheat if HTTPS is used.
That is not correct.
HTTPS uses transport layer encryption: it protects the message while it's in transport, so the third parties relaying it can't peek at its contents or modify it.
HTTPS does not do anything to limit what the ...