The festival takes place in the fourth month in the Cham calendar to worship Po Rum Pan and other gods. Other Cham groups hold the buffalo killing festival once every 7 years. However, the Cham in Lac Tanh kills a buffalo every year to worship their gods at Po Rum Pan temple. They all like to make a sacrificial offering to them in anticipation of good crops as the main source of livelihood. 

For the slaughter called the Sam Le in the Cham language, villagers choose a strong, male buffalo 3-5 years and tie it to the pole before Po Rum Pan temple in the previous afternoon.

All dignitaries in the village gather at the temple in the evening to ask for permission to kill the animal. At the weak dawn of the next day, they will hold ritual to take a sword from the keeper’s house.

Before the ritual, the chief sorcerer known as Ka-Ing and his two assistants will offer water, wine, tea, betel leaves, areca nut, eggs and 3 baskets of rice to Po Rum Pan, 11 other gods and the dead dignitaries. After the buffalo is killed, they will cook the rice and buffalo meat for the deities in wet rice civilization as a common practice.

After the ritual, every sorcerer will put a red scarf round their neck. Particularly, the chief sorcerer will wear it round his head. He draws out the sword and together with his two assistants and the slaughterer (or the Sam Le) will go through the main gate to the place where the buffalo is tied. The buffalo lies on its side with its face and belly facing the temple’s gate and its back to the sunrise. The buffalo’s neck is over a hole, 40 cm deep and 45 cm wide.

Before the slaughter, they will circle the buffalo three times. Each time, the chief sorcerer uses his right toe to draw an amulet on the ground to call on three gods to come to guard the buffalo. After that he will wash the buffalo’s neck three times with water and use a piece of earth to draw an amulet around its neck. He whispers the wishes of villagers into the buffalo’s ear and asks it to bring them to the gods.

After praying, he will use the sword covered by leaves to slaughter the buffalo symbolically and then hand it to the Sam Le. The Sam Le asks the animal to go to heaven to enjoy more cooking and water there. He says villagers will offer the buffalo’s meat to Po Rum Pan and other gods, the bones to the god of earth and sand, the hair to the god of fire and the blood to the god of earth. He then will use water to clean its neck three times, press his finger to the sword and then cut its neck.

In this process, the Sam Le always presses the sword to the buffalo’s neck which is covered by leaves to hide the slaughter from the gods. Meanwhile, the sorcerers will keep away from the buffalo and look to the East. They must not look at the slaughtered buffalo.

Before returning the valuable sword to the temple, the Sam Le will throw the blood-stained leaves to the hole and pray to the soul of the buffalo. Then, the chief sorcerer will use the sword to symbolically open the buffalo’s belly, and together they go back to the temple.

At the entrance, he will use the sword to get the banana leaves off the top of a wine jar and ask the gods to enjoy the wine with a roasted chicken first, while villagers make different dishes from the buffalo meat. Only the buffalo’s legs, tail and ears are kept raw; its tongue, eyes and brain are put on to boil.