Body Swapping / Shape Stealing - extracts from the Game Design Document

BODY SWAPPING / SHAPE STEALING

When the protagonist’s current physical form reaches -10 HP (a nod to D&D) the body dies and the spirit detaches.

The spirit is immune to virtually all forms of attack and is merely repelled or displaced by others.  i.e. a spirit can be caused to flee - which means it drifts swiftly away from the direction of the ‘attack’ for a pre-determined period of time (a counter is visible) during this time the player may move up and down only.  Or a skilled enemy may be able to teleport the spirit to a random location - this can be quite far away in some cases!

A detached spirit may inhabit or possess any other ‘open’ or in other words, 'accessible' creature type (some creatures, like ghosts, are ‘closed’, i.e. they can never be possessed as they have no physical form in which the spirit can reside).

There are restrictions to possession of body-swapping or shape stealing as it is sometimes called.  The level of the creature MUST be less than the level of the protagonist.  This is the penalty conferred to ‘death’, i.e. you cannot possess a more powerful creature than yourself.  Also the time it takes to possess a new shape is one minute minus 10 seconds per level difference.  So a 10th level protagonist possessing a 6th level mermaid will take 20 seconds to complete the possession - during which time they are vulnerable and effectively stunned.  The only action they can take is to abort the attempt and move on.

Being in spirit form has many additional effects.  The protagonist is invisible to most creatures, and may induce temporary fear in others.

Additionally, a spirit may pass through certain barriers and may flip switches and levers, move objects and generally interact with the environment to a limited capacity.  This capacity is determined by an ‘ectoplasm’ meter.  This slowly builds up over time and is consumed when interacting with the physical plane.  A spirit can even ‘shove’ creatures, pushing them off precipices or on to traps.

The spirit form has its own upgrade path which may make the ectoplasm pool larger, recharge rate faster, or confer immunities or resistances to certain attacks or even allow the advanced protagonist to attack from spirit form, or detach at will.