There is plenty comic relief provided in the first few scenes of ‘The Time of The Doctor’ from the Doctor turning up for Clara’s Christmas party nude. While funny the idea of hologram clothes could be a useful addition to any campaign.
The projector takes the form of a small pill (which Clara chews prior to swallowing). Rather than projecting an image it puts it on to the eyes of those observing. This projection can be for a single person or either anyone who looks at them or many individuals.
There is still a holographic shell which can provide heat, which prevents the Doctor and Clara from freezing to death when they are beamed down to snowy Trenzalore. There is presumably less weight, as Clara says earlier that it doesn’t feel like she is wearing anything.
Hologram clothes are ideal for time travellers to allow them to blend in where ever they go, as long as you remember to set them to project to all observers. It isn’t clear how you program them but it could be through mental command, a wave of the sonic screwdriver or even based on what the observer expects to see.
PCs could have their characters instantly wearing clothes appropriate to whatever time period they find themselves in or matching the local alien fashions for any planet. It could even let them don uniforms, letting them infiltrate organisations.
We don’t know whether the pill just has one setting or whether multiple observers could each be sent a different image. This could be useful as witness descriptions of those using the hologram clothes would all differ.
It could be possible to extend the hologram further, disguising their physical details such as race, age and gender. This would allow alien PCs to avoid causing a commotion on Earth (especially in historical adventures) and for human PCs to go unnoticed on exotic alien locales.
This opens the possibility of setting adventures amongst hostile aliens. PCs could find themselves behind enemy lines on Dalek or Cybermen ships or planets. As long as their disguise works they have the chance to mix with these races and learn something more about them.
It is possible that the holographic shell might provide not just heat but other forms of protection. If it has an integrated force field and oxygen supply then it could allow PCs to survive on worlds where they wouldn’t normally be able to live, further expanding places for you to set adventures.
There are far nastier uses of technology that projects illusions directly into a subjects visual cortex. For example the same technology could blind someone or make them see something terrifying and they wouldn’t be able to turn away or close their eyes to block out the image (since it is in their brain).
It should be noted as well that the only reason that the Doctor and Clara had to be naked was because they were going to church. The holographic clothes could work over normal clothes, sparing PCs embarrassment if it suddenly stops working or they forget to project its image.
Tasha Lem indicates that you can be trained to see through holographic clothes. Since it is being projected directly on to the visual cortex this could mean that their minds are able to filter out the illusion.
We don’t know how long the pills work for. Since they are consumed they enter the digestive track and would likely be dissolved. This sets a time limit on how long they are active, which you can determine. This could be very awkward if the hologram clothes vanish at an inopportune moment.
If PCs want to use them frequently then they’ll either need a constant supply of the pills or there could be an implant that performs the same function. Just how available they are will depend on how easy you want to make it on the players.
From Tasha Lem’s comments we can assume that this technology isn’t unique to the Doctor. This raises the possibility that PCs will encounter others using the same technology.
While this could just be a minor background detail for a NPC it could also serve as a basis for an adventure. As noted above hologram clothes make infiltration and invasion much easier. How can PCs spot an enemy who can blend in perfectly or change their clothes in an instant?
Variations in technology could mean that the hologram clothes don’t work perfectly with all visual cortexs. PCs might be immune to the illusion projected by an alien’s clothes, allowing them to see the truth or an NPC might not be able to see their clothes either placing them in danger or revealing that the NPC isn’t human.
PCs could investigate reports of demons and other horrors only to discover that they are just illusions being projected by similar technology. Similarly a wave of blindness through a population without a medical cause could be the result of their visual cortex being manipulated.
You could explore the ramifications on planets or time periods when this technology is common place. The construction and sale of clothes forms a large part of the economy so how would that affect things when you no longer have to wear real clothes? How would fashion change when you don’t have to worry about the physical realities of a garment and project anything on to a visual cortex?
Holographic clothes are incredibly convenient and avoids the need for a craft with a wardrobe. PCs can travel very lightly making it useful for groups without a TARDIS. It would be a real boon for UNIT or Torchwood officers who have means to travel in time without a Time Lord, using either a vortex manipulator or time portals.