Ta'ziyeh means consolation, and everything in the form serves the work of grief. The plays enact the events of Karbala: Husayn and his small company surrounded on the plain, the denial of water, the deaths one by one, the martyrdom of the Imam himself and the captivity of the survivors. The conventions are fixed and openly symbolic.
The protagonists, the family of the Prophet, sing their parts in classical Persian modes and dress in green and white; the antagonists declaim without melody and wear red; a change of headgear turns one performer into another, a basin of water stands for the Euphrates, and circling the stage signifies a journey. The staging is in the round, traditionally in the takiyeh, a courtyard or purpose-built arena, with the audience wrapped around the action and fully complicit in it: they know every line to come, they weep, beat their breasts and cry out, and their weeping is the point, since tears shed for Husayn are held to intercede for the one who sheds them.
The actor playing the villain Shemr may pause to protest that he too loves the Imam whose killer he must portray, a convention that keeps the moral frame unbroken. Performance is concentrated in Muharram, above all on Ashura, the tenth day, and a full cycle can run through the month with a different episode daily, the whole community underwriting the production as an act of collective devotion.