This set of criteria will help guide you in understanding our star rating system.
We use a 5 star system. We do not, however, use fractional stars. We try to commit one way or the other. 

Five stars - A release that could be of particular importance or significance; a potential classic with an appeal or quality that transcends personal taste. A five-star game is among the best the hobby has to offer and as such is expected to have a positive impact on it as a whole. These are the "Great" games.
Four Stars - An especially well designed, well made and presented game with much to recommend it especially for fans of similar titles. Four stars also indicate an exceptional design that possesses superlative qualities which may attract players beyond genre, setting or concept.
Three Stars - An overall average- but recommendable- game that may falter critically, but still has appealing qualities or values that our writers find worthy of note. These are particular games that readers with varying expectations, experience levels, or tastes may rate slightly higher or lower than our review panel.
Two Stars - This is a game that can be considered to be playable but relatively below average. There may be specific issues with its mechanics, setting, themes, rules or production. Games with two stars are not recommended for general audiences, but may be of interest to those who approach them with appropriate expectations.
One Star - A generally poorly designed or poorly made game that has little to recommend it. Reserved for titles that have notable problems that fundamentally impact playability or that have serious quality concerns. Games of the lowest rating may be poorly playtested, haphazardly developed, and are considered by our reviewers to be substandard or not recommended for most players.