Like o-mamori these may act both as amulets to ward off misfortune and as talismans to bring benefits and good luck. O-fuda are obtained equally from Buddhist temples and Shinto shrines. They come in various sizes and typically comprise a flat and slightly tapering piece of wood (sometimes paper) on which is inscribed or stamped in black and red ink the name of the shrine/temple and the kami enshrined. The o-fuda is wrapped in white paper and tied with coloured thread. O-fuda reflect the riyaku and shintoku of the shrine or temple.
A Popular Dictionary of Shinto. Brian Bocking.