Scarves don't have any special effects. They increase body armor by +1. A player who can't afford a Platinum Amulet should wear a scarf. This item will be bought in Edron and sold for much higher prices to a Free Account (who is unable to travel to Edron to buy his own). It is also posible to get them at the daily scarf spawn inside a corpse that you can reach by entering the desert dungeon and going all the way down and then in the room with the spiders all the way up. You see a Poison Spider and a corpse with a Book, a Rope, a Shovel, a Leather Armor, a Leather Boots, a Torch and a Backpack.
