You are not allowed to give x away for free.

forum?

Nope

chat?

It's allowed to post beta keys on the forums, just not to falsely post them as full games using engine for giveaways.

When you give something away using the site, you don't entirely do it for free. You get contributor value out of it. Hence this rule. Give them away on the forum or in the chat.

You can give them away in the forums or chat.

Noone's stopping you from giving away the keys on the forum or in the chat room. You simply cannot make a giveaway for them because they would not work fairly in the context of the point and contributor value systems as they are set up at the moment.

It might be worth suggesting that new entries be offered (perhaps valued at 1 p) for beta key giveaways for popular titles.

Okay. Next time I make a giveaway, I'll ask all of you for money.

You can give them on the forum away. Betas aren't allowed because they aren't the full game. For example if you create a giveaway for Ravaged, the winner wants a full game and not a beta, because the giveaway was for the full Ravaged and not the beta. And another reason is that people want contributor value and they don't deserve it when they make only a giveaway for a beta key (which are mostly free).