Valve has been waging war against review manipulation for some time now. Back in September, it began adding histograms to review pages to allow users to see if a game has been subjected to review bombing. Steam implemented the measure after both Firewatch and GTA V were bombed following takedown orders filed against popular YouTubers. Since then administrators have noticed another type of manipulation involving how reviews are ranked on the site.

As with many other websites that offer user reviews, Steam allows visitors to rank reviews as helpful or unhelpful. Ideally, and indeed on most other sites, this works well in pointing users to the most useful reviews when considering a purchase. However, Valve has found that users with a gripe are also abusing this system.

It works in much the same way that upvoting works on Reddit. After reading a review, users can mark it as helpful or unhelpful. The most useful reviews float to the top of the list, so they appear before others. At least, that is how it is supposed to work.

What Valve discovered though, is that some reviews are being unfairly marked, usually with an aim to impact the game negatively.

"It turns out that not everyone is as helpful as we would like. Instead, we are seeing more and more feedback from players that the helpful reviews shown on store pages aren't representative of how well people are actually enjoying the game."

According to Steam, 11 million people have used the review ranking system. Most of them are using it as it was intended. However, it has found some users appear to be manipulating reviews by marking negative reviews as helpful and positive reviews as unhelpful (or vice-versa). It has recorded some accounts ranking as many as 10,000 reviews on a single game.

"This behavior is not only humanly impossible but definitely not a thoughtful indication of how 'helpful' each of those reviews were," said Valve.

To combat the situation, Steam will be implementing a couple of changes to the system.

First it will change the way reviews are ranked by taking into account users who appear to be trying to influence the system.

"Ratings from users that follow normal patterns of rating will continue to be counted the same way that they have, whereas accounts that rate an excessive number of reviews on an individual game will see the weight of each individual rating count for less and less."

The second change will be on the store pages themselves. Each page will show helpful positive and negative reviews proportionately. If a game has 80 percent positive reviews overall, then the store page will display the top eight positive and the top two negative reviews.

The changes are being beta tested starting today, and for now, users can turn the new system on and off with the "Review Beta" dropdown to see how it affects the review rankings.