The Maya believed in blood sacrifice. Blood letting was common. At some festivals, the Maya would cut themselves so they would bleed. This was one way they offered blood to the gods to keep their gods happy.
Sometimes, they sacrificed animals, especially goats. On occasion, when the need was great and their problems were many, they also used human sacrifice.
When they had to sacrifice a person or an animal, the priests first painted them blue. That was the sacrifice color of the ancient Mayas.
One way a human sacrifice was conducted was to throw the victim down a well. If they were still alive by morning, obviously the gods wanted that person to live. But some people were not given a chance to survive. They were simply killed.
Most human victims of sacrifice were slaves. But anyone could be chosen. The selection of what or who would be sacrificed was up to the priests. Their decision was final. That gave the priests incredible power.