Valve has admitted that Steam reviews have a bot-brigading problem, and now it's finally decided to do something about it.
As part of an effort that's already included anti-review-bomb charts, Valve has taken aim at yet another pernicious element of Steam reviews: vote manipulation.
In short, it's possible to rate reviews as "helpful" or not, which increases their prominence on a game's store page. For quite some time, people have been using bots to swing this functionality in their favour.
In a blog post, Valve acknowledged this issue, saying that Steam reviews currently allow "a small group to manipulate reviews to a degree that is clearly decreasing the value of Steam for many other players."
To solve this problem, it's doing two things: Soon, "helpful" ratings from accounts that are "far outside the norm" will be weighed differently than those of regular, presumably human, users. "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," wrote Valve.
Additionally, reviews will also be sorted differently on games' pages, with top reviews appearing in a way that reflects a game's overall score. "For example, if the game is reviewed positively by 80% of reviewers, then the ten reviews shown by default on the store page will be 80% positive, showing eight positive and two negative," wrote Valve.
In theory, this will make things like review bombs less effective, because even mass upvote campaigns won't necessarily reshape a game's store page anymore. There are ways botters could get around these changes, but some new barriers are better than nothing.
The changes are in beta right now. You can turn them on (or off) by scrolling down to a game's review section and toggling the "review beta" option.