The core mechanic of Critical Role's upcoming roleplaying game uses two 12-sided dice--one is called the Hope die, and the other is Fear die.
When a player makes a check, they roll both dice and add them together, comparing them to a check DC (which goes from 5 to 30, depending on the difficulty). Where the Hope and Fear come in is in the form of a meta currency reminiscent of Modiphius' 2d20 System--the players amass Hope, while the GM collects Fear. Whichever die rolls higher in a check generates a Hope or a Fear point.
These points can then be spent--Hope can be spent by the players for bonuses, and Fear is spent by the GM to add a complication to hinder the players. Players can power special abilities or help allies (giving them +1d6 to a check). The GM spends it on using enemy's special moves, ticking countdowns, adding damage, and so on.
It is fairly similar to the 2d20 System, which is utilised slightly differently in Modiphius' various games using names like Momentum, Threat, and Doom (and, indeed, 2d20 is credited as an inspiration).