Lost Souls are back since season 11 in a new version. See Lost Souls (Archive).
These Lost Souls are of the utmost importance for any town that aims to survive long enough, since their existence can have dire consequences.

Souls found in the desert can be present under two forms:

• The Lost Souls in blue .
• And the Tortured Souls in red .

Each death, whether it be during the day or the nightly attack, will spawn a Lost Soul in the desert.

This event can trigger at any distance from town, and two Lost Souls can spawn in the same zone.

There is no means to disable a Lost Soul from spawning, and all death types will provoke the event.

Lost Souls wandering the World Beyond will be visible on the Shaman’s minimap (at the town’s gates and in the World Beyond):

• Invisible if held in someone’s inventory.
• Visible if dropped back on the ground.
• Visible if hidden in a shunned’s hideout.
• Visible if inside an explorable ruin.
• No visible difference between a Lost Soul and a Tortured Soul.

Lost Souls are always shown wandering between 4 zones, and are always found in the bottom-right zone.

During each nightly attack, a Lost Soul has a probability of turning into a Tortured Soul, independently of where it is located during the attack.

Lost Souls will have no particular effect. Anyone can pick them up, no risk attached.

On the contrary, Tortured Souls have various effects:

• Each Tortured Soul increases the midnight attack (by 4% per soul; with a maximum of +20% in Distant Regions, unknown in Hardcore).
• The pickup action of a Tortured Soul (in the desert) is fatal for a player that is not the shaman, or is not shielded by a potion.
• The pickup action of a Tortured Soul (in town) will not kill the player. (Warning! Dropping the soul in the World-Beyond and then picking it up again, will kill you.)

This action makes the Tortured Soul vanish, and the death of the player that picked up the soul generates a new Lost Soul spawn event, like other deaths.

Purifying souls helps eliminate them and thus cancelling out the negative effects brought by Tortured Souls.
Each purified soul also brings 5 additional defence points permanently. This is visible in the town's defence summary.
The construction of the Hammam is a must to purify souls. This action is available to all citizens (even non-shaman) in ¨My home¨ while a soul is present in your rucksack or coffer once the construction is built.

Lost Souls and Tortured Souls are not recovered when shunning a player.

Lost Souls and Tortured Souls share the particularity of being fake heavy objects.
Meaning, that except the Shaman that can carry more than one in his rucksack, every other citizen can only carry one at a time.
It is possible to carry a heavy object and a soul (which is why we refer to souls as ¨fake heavy objects¨).

A soul (tortured or not) will give a bonus of 2 personal defence points when placed inside one's home. A soul will bring 5 permanent defence points when purified via the Hammam.

Both distinctions are obtained once a soul is purified in the Hammam, the first is personal and only awarded to the player which purifies it, the second is awarded to the entirety of citizens still alive during the purification.

Distinction	Icon	Reason	Rare
Soul Purificator		The number of dead citizens' souls you purified.
Mysticism		The number of souls your town has managed to recycle.

NB : the descriptions are bit confusing since they date from the first Shaman's apparition, when these distinctions were awarded differently.