read the FAQ section (frequently asked questions). You are allowed to look at past games, databases of games and opening books.
Cheating is using a computer to make a move or discussing your game in progress (actually, discussing possible moves and strategies, not just telling someone else that you have an interesting game that they might want to watch).
This is the main point about cheating: If you cheat, you may win, but it isn't YOU who actually wins, it's the computer program, or the other player who actually wins. All a cheater wins is a higher rating for the RHP chess name and identity. RHP players who have ratings that go way UP and then way DOWN are suspected of cheating sometimes. There's more evidence of cheating when they drop way down to enter tournaments and get matches at lower ratings than their actual strength, then once in those tournaments and matches, they beat other stronger players easily. It looks like they are cheating, even if they aren't.
Not everyone whose rating goes up and down is a cheater. Some TIME OUT due to sudden illnesses or work projects, or simple overload by underestimating the count of games that they were getting into.
It's good policy to refrain from accusing others of cheating. If you suspect a cheater, just send your suspicion to the RHP moderators through SITE FEEDBACK at the bottom of all pages. Also, no one forces you to play cheaters. As a reputation for being a suspected cheater grows, the options for the member go away. They are sometimes booted from well run clans. they get barred from tournaments. AND, they get kicked out of RHP.
Time wounds all heels!