One of the changes we're contemplating for CHILL:Into the Unknown is an update to the basic die mechanic. Currently we're testing a Higher is Better (HIB) percentile (d100%) method. The playtest document explains it thusly:

Higher is Better: In nearly every instance, a higher roll means more success or stronger results. Be careful, though, because rolling too high can "bust," just like in blackjack: Roll too high and you'll go over. You want a trade-off between rolling low enough to succeed, and high enough to succeed well. When you're counting up your envoy's traits, higher is also better: a high Strength score is more effective than a low Strength score.

Taking Action: Once your envoy enters a mystery, he'll use his skills and edges to take the fight to the Unknown. Using skills isn't a certain process, though, and fighting Horrors is especially risky. It's all too possible to suffer some failure or setback in the course of the mystery.

When your envoy takes action, you roll percentile dice. Check this against the trait + skill total for the skill you're using. You want to roll high; the higher you roll, the better you do. But, if you roll over your trait + skill, you go bust—you fail in your task. For example, if your envoy has a trait + skill total of 85%, you want to roll as high as possible up to 85%. If you roll low, you succeed in the task, but a roll of 80% succeeds better than a roll of 5%. If you roll over 85%, then your envoy “busts,” and fails in the task. If you roll doubles, like 44% (good) or 88% (bad), you gain a dramatic result, and your envoy may gain some special benefit (or problem!) in addition to succeeding (or failing).