Tabula Rasa

This spell allows willing creatures to relive a memory and to potentially change it. If the memory belongs to the sole target of the spell, it enters a trance state, becoming Unconscious and ceasing to age as it relives the memory. If the memory belongs to a second target, both creatures enter this trance state, with the one experiencing the memory firsthand being called the actor and the memory's source being called the witness. The memory in question can span any length of time and does not need to be remembered in great detail, but the duration relived and affected by the spell must be contained within at most a single 24 hour period, which the targets experience in real time.

At the end of the duration, the actor remembers everything that had happened, while the witness's original memory is overwritten with what had happened during the spell (if both are the same creature, its memory is overwritten). When present, discrepancies between the altered memory, other memories, and reality may cause the witness to realize its memories have been tampered with, though it may also remember that it willingly chose this along with the caster or actor of this spell.

When reliving the memory, the actor takes control of the witness's body within the memory as the witness simply watches from the actor's perspective. The two cannot interact with or communicate with each other in any way. Both targets use their current levels of knowledge and awareness when experiencing the memory. The actor retains its own personality, memories, and Intelligence, Wisdom, and Charisma scores (including skill and saving throw proficiencies involving them) but everything else matches what the witness remembers possessing at the time of the memory (excluding Hit Points). This discrepancy can cause oddities, such as the actor suddenly having access to different class features until the spell ends.

This spell does not cause the targets to go back in time, meaning targets cannot acquire definite knowledge they would have gained if the witness acted differently in reality at the time of the memory, but the spell does create a believable world for those experiencing it; gaps in one's recollection are believably filled in and may even use the witness's subconscious in doing so, exposing details outside of its usual awareness. Should the memory be too vague, the events and sensory information created by the spell may be wildly inaccurate to the events that occurred, assuming they ever happened.

When within the memory, the actor can choose to relinquish its control or to regain it. Relinquishing control causes the actor's decisions and the events to play out as the witness remembers, preventing the memory from being altered. The DM may decide when (if ever) relinquishing control is no longer possible should the actor change important aspects of the memory to the point that it is too detached from the witness's recollection.

The spell ends early if the actor or witness are reduced to 0 Hit Points, or if either of them or the caster chooses to end it early. When this happens, each target forgets what it had experienced from this casting of the spell and the original memory is unaffected. These lost memories cannot be recovered. Any damage taken by the actor within the memory is taken as Psychic damage by both the actor and witness in reality. Being healed in the memory can heal any Psychic damage taken from it, but not other wounds, including Psychic damage from other sources. Conditions and other effects do not carry over and only affect the actor within the dream, but they can still cause either target to take more damage until the spell ends.

Any willing creature in physical contact with the witness for the length of the casting will join the witness as it experiences the memory, but this creature can also leave at any time without affecting the actor or witness in any way, causing its memories of the spell to be permanently removed as normal. These additional creatures do not take Psychic damage from the spell.

Using a Higher-Level Spell Slot. When using a level 7 spell slot, the memory can span at most a single 7 day period. When using a level 8 spell slot, it can span at most a single 1 month period. When using a level 9 spell slot, it can span at most a single 1 year period. Regardless of the duration, at most 24 hours will pass in reality, with the amount of time that passed being proportional to the time spent within the memory compared to the period's maximum possible length given the spell slot used.