Escalating Moral Stakes
Raising the ethical price of winning with each part of the story. Every compromise the characters make leads to a worse one, until they can't go back.
The Treasure of the Sierra Madre
Dobbs' paranoia grows in steps. First it is reasonable, then excessive, then murderous. Each step is caused by the one before it, so his mental breakdown feels like it had to happen. I feel like the gold never really corrupts Dobbs. It removes the conditions that used to keep the worst parts of his character hidden.
1492: Conquest of Paradise
The first meeting with the island people is friendly. On the second trip, the men Columbus left behind turn out to be dead. Later the natives are forced to mine for gold, and the nobleman Moxica cuts off a man's hand when he finds none. Each step makes the next one harder to undo, until the island is at war.

