The major cultural rituals of the Incas dealt with war, agriculture, and life-cycle passages.
War rituals were primarily meant to fortify the Inca's military forces and diminish those of the enemy. For example, in one pre-battle ritual a llama was kept without food in hopes that the hearts of the enemy would become as weak as that of the llama's. On the opposite side of the battle, the Inca would walk over the bodies of their conquered enemy and chant, "I step on my enemies." It was important that the person who performed this ritual strongly exemplify maleness because the Incas associated their forces with dominant masculinity, and those of the defeated enemy with subordinate femininity (Classen, 57).
The agricultural ritual called the hailli follows the same lines of the rite of stepping on the enemy. It involves breaking the earth with a foot plow and much singing. As the cultivation of that specific piece of land continues, the Inca would assign the traditional farmers to farm the land and, with every full moon, sign a ritual song at midnight. Supposedly, the Inca believed that the earth and the moon were connected and, hopefully, as a result of serenading the crops under the full moon, the earth would yield better crops.
The most fundamental Andean ritual is that of an exchange. It involves offering a cup of chica , a type of tea, to someone and drinking a cup oneself. This is not only a gesture of hospitality but also served to integrate separate bodies through a sharing of fluids. On the simplest level this ritual would take place between friends. However, on a more complex level, it would seal an alliance between two social bodies. For instance, when the Inca drank with the leader of a conquered people, the two sides would form a temporary truce.
The Incas also performed many rituals that accompanied rites of passage. Marriage exemplified the Andean cosmological ideal of man and woman, the union of complementary forces. The basic Inca marriage ceremony was quite simple. It started by having the couples hands united by a local representative. This signified that from then on, the couple should function as one (Classen, 61).
Rituals of all kinds played an important role in Inca society. They provided a basis for the cultural ceremonies of the Inca.
From Josh Marcy's, Topher Wilkins' and Adam Tarnoff's ID1 paper.