Why is it legal to set rules for people to review your product?

[Alby_da_Wolf]

Hapimeses said:
In short: the intellectual property (IP) used in the review is privately owned. If you want review code early -- i.e.: you want access to their privately owned IP before the rest of the market -- you may be requested to sign the equivalent of an non-disclosure agreement, limiting your ability to freely talk about their IP. However, once that IP is released freely on the market, such limitations come to an end for obvious reasons.

So, if you want a review potentially filled with spoliers, or discussing aspects of the game that the publisher does not wished to be discussed, wait until after the game has had its official release.

That's about it. Nothing especially sinister, although it does pass control to the IP owners rather than the reviewers. And given most reviewers want their reviews out early, they sometimes have to sacrfice their free speech in the short term to achieve this.

For me it's fine if they don't call it a review. Instead they can use preview, scoop, breaking news, etc, seasoned with all the superlatives that are perfectly fine with marketing, even with a hopeful preview of a promising title, reserving to confirm them later or not with a true, thorough review,  but should be left out of a serious review unless they are fully justified (i.e. for titles really deserving more than 94/100 even without developer/publisher pressure).