A ritual is a ceremonial formula employed to carry out a magical action. While majority of the rituals consist of alters, candles and mystical symbols while speaking in ancient languages, not all rituals have these demands. Some rituals might consist of other requirements, such as fasting, herbal ingredients, specific moon cycles, and more. While the majority of rituals are accompanied with spells, some rituals can produce an effect simply by creation.
Rituals are one of the most common methods performed to achieve a magical effect. Rituals vary greatly in their composition and requirements, but are essentially a supernatural tactic with the power to produce a desired result. What these results are range from modifying one or more aspects of reality to reshaping the very nature of the entire world.
There are a number of rituals that have been shown in the series.
Ritual to put the Witnesses to rest
When the Witnesses rise, Bobby discovers a ritual that will put them all to rest, but it needs to be performed over an open fire, thus leaving the caster vunerable to the spirits as they perform the ritual. Among the ingredients needed are opium, hemlock and wormwood. A symbol must be drawn on a flat surface and the ingredients mixed in a bowl over it as a spell is recited. Once the spell is done, the ingredients must be tossed into a fire which will then send out a wave of energy that puts all the Witnesses to rest.
Spirit Summoning Ritual
The ritual is used to call upon someone already dead in the form of a spirit. It consists in having prepared four lit candles at the ends of a squared paper with a ritual circle on it and an object belonging to the deceased, and a bowl with herbs at its side, in the center of a circle made of salt. The performer recites the following incantation in Latin: "Amate spiritum obscure / Te quaerimus / Oramus nobiscum colloquere / Apud nos circita", as he makes the circle of salt and, at the end of the incantation, throws a lit matchstick at one side of the paper without burning it.
There are no details about the composition of the candles and which herbs are used in the mix, as they probably need special properties to summon the spirit (though, they can also have no special components).
It appeared in the chapter "Weekend at Bobby's", in which Bobby Singer used it to call upon Gavin MacLeod, Crowley's son from the time when he was still human. To do so, Bobby used a ring that Gavin had when he was alive.
Demon Summoning Ritual
This ritual can be used to summon demons, and it consists in having a bowl with mixed herbs alongside seven lit candles in a specific order with lines that connect them (this can be done with chalk). To effectively perform the ritual, blood must be offered by dropping it on the herbs, while reciting a Latin incantation: [...] "Et ad congregandum / Eos coram me". At the end, a matchstick must be thrown at one side of the bowl.
It appeared in "Weekend at Bobby's", as it was performed by Bobby Singer to summon the demon, Crowley. Sam and Dean later perform the ritual in "Meet The New Boss," "There Will Be Blood" and "Survival of the Fittest" to summon Crowley when they need him. The last time, Crowley doesn't appear immediately as he is within a Devil's Trap, but comes later, having heard the summons.
Reaper Trapping Ritual
Demon Killing Ritual
The prophet Kevin Tran discovers a ritual in The Word of God that completely obliterates demons and the people they are possessing, but passes it off as a ritual to open the Gates of Hell, tricking the demons into bringing him the necessary ingredients. Once all of the ingredients are in place, he drops a lit match into the bowl of ingredients and a wave of energy is emitted that disintegrates all nearby demons. Performing this ritual allows Kevin to escape Crowley.