Time travel stories are scarce in Mythic Europe. They are a mainstay of our genre fiction now, but they were revolutionary when, in the Nineteenth Century, they became popular. Folklore does allow a limited form a time travel, in that the faerie-led can be held far from home for centuries, effectively moving forward in time without aging. There isn’t, however, a genre where people are allowed to go backward in time.
This is less strange than it appears when you remember that, in medieval literature, things are not much different in the past. When Julius Caesar is described in some sources, he is a medieval king, his soldiers medieval knights. There’s little interest in going back in time, because going back is much like travelling to another country now. Time travel isn’t needed, because ghost stories and stories of strange, distant lands fulfil the same narrative need.
What’s to be done if we want them anyway?
What did medieval people think Time was?
Let’s consider the absence of an Art of Tempus.
What is time?
In Artistotle’s view, which was followed by Aquinas, time is not a thing. Time is what you see when you count the process of things happening one after another. As such, time is perceived. Before humans were around to watch things there was no time according to Aristotle, because there was no-one who acted as the observer. Things happened, but lacking an enumeration, there was no time.
Aquinas, being a Christian, has an omniscient observer available. Time occurs because God does stuff to begin Creation. The first day is literally the first day in Creation. Time is surrounded by eternity, which is effectively timeless. Again, things still happened prior to people, but it doesn’t matter, so there’s no time.
Time is, then, the observer noticing motion. This means it’s perceived, not abstract. In the Fourteenth Century, some thinkers suggest this is mistaken, that there can be time without motion, or without observers, but that’s after the game period.
No noun? No Form. No form? No Art. No Art, no spells.
That’s no fun…what can we do?
Declare Aquinas wrong?
One way out of this is to say that time does not work in the way suggested by Aristotle. In the Criamon philosophy, for example, Order descends into Chaos, and this creates an energy differential which can be used by magi to fuel spells. The motions in the field of vim that circles the Earth are literally the clockwork of the universe winding down into utter chaos. This means that manipulating time is Vim.
When you misuse the magical field of energy, reality drops you outside, in Twilight, and even alters you, so that you won’t keep breaking the underlying structure of the Universe. Twilight Points are, therefore, the perfect penalty for characters who damage time.
As an example, in one of my earliest online games, we got around the slow signalling rate of email games by having the players simultaneously play three stories. The player had the same magus in each story, and if they did things in the chronologically earlier stories which could not fit in continuity with the later stories, the the later characters just earned Twilight Points.
One way travel
Getting to the future is easy. Faeries have the ability to store people for a prolonged period, so that they move forward in time. Similarly, certain regios have dilated time: a person living in one might age very slowly compared to the outside world. Some spells turn a person into an unaging material object, and they can resume their life if the object remains undamaged until the Duration ends. It’s returning to the present which is difficult to explain.
Back from the future
To state the obvious: God gets to cheat. This is now things like prophetic Visions occur. God just shows people a bit of what he can see, in his extratemporal position.
Demons cannot affect the past, because they are unable to plan. As purely reactive creatures they aren’t able to decide to travel to the past as part of an elaborate scheme.
Faeries cannot send a character back in time. They can, however, portray flawless imitations of historical times. This means that a character who has gone forward in time by another method might be tricked into thinking they have travelled home.
If Criamon cosmology is correct, and Time is a circle, outside of which is Twilight, then Twilight might be used to traverse time. Some of the earliest mentions of Twilight in Ars Magica state that it is an eternal realm, outside the universe. Further they list reports, by magi who have travelled there, of meetings with the remnants of magi who had not yet fallen into Final Twilight, or even been born. This clearly allows information to be passed backward through time. It makes the Bootstrap Paradox playable.
The Hall of Heroes, where the ascended mortals exist, does not seem to be outside of time in quite the same way as Twilight. The Aspects sent by heroes into the world show no anachronistic knowledge.
So, travel through the Magic Realm allows information to violate strict causality, which is to say, travel in time, but not necessarily through every and any part of the Magic Realm. In much the same way that there is a Deep Faerie where mortals do not go, perhaps there is a Deep Magic, wherein Twilight lies.
If information can be exchanged in this way, might it be easier for characters in spiritual form to travel time? If the characters can see historical events, but not interact, then they can take actionable information, but not create paradoxes. Might it be simpler to send oneself through time as a ghost? Do certain prophetic dreamers do this already?
Travel may be environmentally dependent: in that characters can only leave and re-enter time at sites with a Magical Aura of 10. These places are sometimes destroyed, for example by the encroaching Dominion, or are transitory. As an example, some places have an Aura which rises during the equinoxes, which s why the Aegis is cast on those nights. This means that although a character can go to a place via time travel, they need to remain there only for a certain amount of subjective time.
If you can travel time as a ghost, can you create a solid form once there if you know the secrets of the Nightwalkers, and the construction of a solid, distant body (called a phantasticum)? This might allow time travel much like the “straying” used by Nightwalkers, except it is somewhat safer because if you become lost in the past, you have a lot of time in which to re-orient yourself, as you come the slow way home. Phantastic travel also prevents you bringing objects back with you (save by, for example, burying them in a safe place) which makes time travel, in some ways, more playable. Characters cannot mine the past for physical resources.
The Axis Magica creates a cynosure for spiritual travel. Is there a similar cynosure for chronal travellers? I’d argue that the changes of eon should be obvious. The Silencing of the Oracles, for example, or the spread of the Dominion. Finer levels of control probably require a Lore, much as geographical navigation does.
As a plot idea: the characters may be the ones who construct this beacon, as a Saga goal. This solves the problem of why they have not seen any other time travellers: no-one travels before the creation of the beacon. Afterward, all bets are off, as future people can bootstrap.
What can we change?
That’s saga dependent: cosmological arguments can be made for and against people within Time having sufficient agency to change what happens. There are also questions regarding consequences: if you create paradoxes, does the universe care? Does God send an angel to edit you out of the great play of redemption? Different levels of constraint provide a different feel to the stories, because they provide players with different types of challenge.
History is set: your presence can’t really change anything. All attempts have, in a sense, already failed. Players in these sorts of games need to game the historical record. They need to find loopholes in the known facts. This works well for games where the troupe do not want the characters’ “present” to change.
History is infinitely malleable at major points. Player characters can save Arthur, or prevent the fall of Constantinople. This rewrites the world they go home to. This allows epic stories where the players get the broadest scope to rewrite the world.
History is trivially malleable. The most famous story of this type is by Ray Bradbury, where the death of a butterfly in the ancient past affects the traveller’s present in dramatic ways. In these sorts of sagas, players need some way to know that the effects of their actions, what small adjustments they can make, and some sort of opposition. Terry Pratchett has an order of monks in his stories who curate these little coincidences.
History is unknown. If your characters go to ancient Egypt before the Flood and do virtually anything, then either the narrative or the effect of their actions is lost to history, so it’s not simple to tell if history is malleable. One way is by attempting to make a change notable in the far future, and seeing if all attempts fail due to odd circumstances.
Change both happens, and does not happen. In this case, Time contains discontinuities. These are spackled over with a scab of mystical energy, that forms a Twiluight scar on the magus.