Stakes
Also said as What is at risk, What you stand to lose
What will be lost if the hero fails, and what makes that matter to this particular player. Small and personal usually beats vast and abstract.
A world in danger has been used so often that it means nothing. A dog the player has been feeding for ten hours means a great deal, and in a game it has to be something the player knows they can actually lose.
Say it
“Raise the stakes: the companion the player has spent five hours with can die in this fight, permanently, and it depends on whether they finished the side quest.”
Where you’ve seen it
Mass Effect 2's final mission can kill any of your crew for good, including Shepard, and the dead stay dead when you bring your save into the next game. The whole game has been getting you ready for that risk.
Not to be confused with macguffin
The MacGuffin is the thing everyone is chasing. The stakes are what happens if they fail to get it.