Omens
the small luck a doomed creature spends to keep the dice from killing them
Characters begin play with a class-dependent number of Omens (often d2, sometimes more for the lucky-cursed) and regain a handful on a full night's rest. An Omen can be spent to reroll any die, add or subtract d6 from a roll, or negate an enemy's critical hit — the small superstition of a small life pushing back against the prophecy.
A few items in the dying world interact with Omens directly. The One-eyed One-legged One-winged Gull sold by Mikhael the Merchant "allows you to reroll your Omens gained when resting" — a useless squawking gull that costs a portion of the buyer's soul and pays out in marginal luck. The Calendar of Nechrubel turns regardless.
One-eyed One-legged One-winged Gull, Mikhael the Merchant, Gutterborn Scum (begins with d2 Omens), Calendar of Nechrubel
Whether Omens are a tally of personal premonitions, residual divine favour, or simply the GM's mercy-token is unwritten. The cap on Omens carried — class-dependent or hard — varies by reading. Their cosmological status (do they cost the world something when spent?) is silent.