Props are any objects placed in rooms that cannot be destroyed through conventional means. Props can range from pieces of furniture, to bits and pieces of pipes, rocks, and various other objects. Props serve the purposes of being obstacles, providing cover, and dividing the room into segments. Often times, enemies will be startegically placed around the props to make dealing with them more difficult.
Other times, props may be surrounding useful items such as Edgewood meritous tokens, or juice boxes. There are various types of enemies that can ignore the boundaries of props, and many forms of attacks that can destroy the props entirely. Often times, props may also double as hazards, and will become capable of damaging the player. Various boss type enemies use props as part of an attack, such as The Frozen Few.