"Random Number Generator" (or "Generation"), randomness in Gwent or an instance thereof.

In Gwent, high RNG cards, such as Zoria Runestone, are seen as bad by some players as they come with high variance and their value can fluctuate widely. This makes them unpredictable. Another instance of high RNG in CCGs is draw RNG during the mulligan phase which can culminate in a topdeck battle.