A Threshold is the category of death the Bound are placed into in Geist: The Sin-Eaters. While not used as a social group in the same manner of Krewes, a Threshold is an important aspect of a Bound's existence, usually dictating what type of Geist they will attract during their moment of death. Once revived, a Sin-Eater will carry their marks of death throughout their lives, using them as part of their personal identity. In addition, at least one of a Geist's Keys will be one of the two keys most commonly associated with a particular Threshold.
There are five Thresholds; each is fairly broad in scope and power, and some Bounds' manner of death may technically fall into more than one; usually, their personality dictates the final choice. Someone who starves to death would obviously be Silent due to denying their body food, but a suicide might also fall into this category, neglected by someone that drove them to the act. More often than not, the Geist they join with originally came from the same Threshold, though there are exceptions to that rule.
- The Torn, also called the Bleeding Ones, who were victims of an act of violence. They manipulate the Keys of Stigmata and Passion.
- The Silent, also called the Starved Ones, who died due to neglect of the body, soul, or both. They control the Keys of Stillness and Cold Wind.
- The Prey, also called the Eaten Ones or Drowned Ones, who met their ends at the hands of Mother Nature. They lord over the Keys of Primeval and Grave-Dirt.
- The Stricken, also called the Ravaged Ones, who were claimed by fatal illnesses. They are masters of the Keys of Phantasm and Tear-Stained
- The Forgotten, also called the Lightning-Struck, who died by accident, fire, or a simple twist of fate, or by a method so unusual it does not fit into the other four Thresholds. They hold the Keys of Industrial and Pyre-Flame.