Need help balancing a science fantasy setting and solving a time paradox

[Uzgul]

Hi, I need some help creating a futuristic homebrew setting with magic.

The plan for my group is, to let them fight their way out of hell (in case of a TPK), but let a few thousand years pass while they are gone. So they will a jump from a medieval to a science fantasy setting. The world will be in a not so bright age after a great catastrophe, that broke the material plane into multiple parts floating in the astral sea (the material plane is an actual plane in this setting).
The technology will be similar to Warhammer 40K. So there will be Chain swords, Energy Hammers, Blasters etc. This way the PCs combat abilities should still be usefull.

So far, so good, here is where I need some help.
1. I will need a lot of homebrew to make this work. So if you know any good source of futuristic homebrew for 5e (in therms equibment other editions might also work), I willl appreciate that.

2. I am not sure how to balance futuristic weapons against magic. An energy blade should do more damage than an ordinary longsword, but that would cause problems balancing it versus caster damage.

3. I might let them go back to their own time to prevent the (literaly) world shattering event, but I need a way to explain it without creating a time paradox. As I play with a group of physic stundents, they probably won't accept "because reasons".
(If they go back to prevent a future, they have already seen, that future would have never existed to be seen by them, so they would have had no reason to go back)

4. If you have any good ideas, just throw them around.

[CNagy]

RE: Time paradox, I'd frame it not as "preventing this future," but rather the opportunity to prevent an alternate reality from ending up in more-or-less the same future. It strikes a balance between doing good (saving a material plane and all of its inhabitants) and personal survival (who wants to live in the nightmarescape that is a 40K future if they could escape to a better time?)

[Ralanr]

Sorry, all I can think about is how the characters of your players will adapt to the knowledge that everyone they knew and loved outside of the party is now dead and possibly lead a full life without them (course I don't know the backstories so I'm assuming).

Time travel is very complicated. Solving the catastrophe would have the party cease to exist because they never entered that world after hell due to that world not existing. And if they never entered that world, then they never learned of the catastrophe and never went to stop it. It wasn't stopped so the...this is why I hate time travel.

[Hudsonian]

I'd be really interested to see what happened if you took some of the combat from something like Titansgrave, and then took your party through flashbacks that used straight D&D stats.

Maybe there is some sort of powerful incantation that pulls a Xmen: Days of Future Past. And right at the end of the campaign any memory of the event is gone, all the characters have HUGE headaches, everybody is level 1. Just the background story has happened for the characters. WHOLE NEW ADVENTURE.

[Shining Wrath]

If technology can advance, so can magic.

Give the martials better weapons; light sabers or whatever. Reflective armor that bounces energy attacks back a la the carapace of the Tarrasque. Soup those boys & girls up.

Then: drop every spell by one level and turn the level 1 spells into cantrips. Homebrew some new level 9 spells.

You'll still need to guard against abuse of Wish and True Polymorph and the like, while providing even nicer stuff for the new 9th. It's a challenge, but probably easier than inventing a whole new magic system.

[Capac Amaru]

Make sure you address the "why haven't a whole bunch of people fought their way out of hell and made it back the same way" question.

[Ace Jackson]

Hi, I need some help creating a futuristic homebrew setting with magic.

The plan for my group is, to let them fight their way out of hell (in case of a TPK), but let a few thousand years pass while they are gone. So they will a jump from a medieval to a science fantasy setting. The world will be in a not so bright age after a great catastrophe, that broke the material plane into multiple parts floating in the astral sea (the material plane is an actual plane in this setting).
The technology will be similar to Warhammer 40K. So there will be Chain swords, Energy Hammers, Blasters etc. This way the PCs combat abilities should still be usefull.

So far, so good, here is where I need some help.
1. I will need a lot of homebrew to make this work. So if you know any good source of futuristic homebrew for 5e (in therms equibment other editions might also work), I willl appreciate that.

2. I am not sure how to balance futuristic weapons against magic. An energy blade should do more damage than an ordinary longsword, but that would cause problems balancing it versus caster damage.

3. I might let them go back to their own time to prevent the (literally) world shattering event, but I need a way to explain it without creating a time paradox. As I play with a group of physic stundents, they probably won't accept "because reasons".
(If they go back to prevent a future, they have already seen, that future would have never existed to be seen by them, so they would have had no reason to go back)

4. If you have any good ideas, just throw them around.

You mention this is all predicated on the notion of a possible TPK. This seems more like the aim of an entire campaign, and not something to pull up as a diversion if the TPK happens. On that note, I'd probably actually just cut to the chase and start the players in hell, and have them be from various time periods. Still, going through only what has been asked.

On point one and two, I think you might be overthinking this from the gamest perspective a little bit. An energy sword might not need to do more damage then a long sword simply because it's energy. I'd treat it more as difference in kind then scale, a longsword which you brought with you out of hell is likely still as useful against common animals as ever, but to hurt people in future armor, you need the energy blade. TLDR; I'd think of energy weapons and future weapons in general as +0 'magic' weapons. This is a little trickier when handling future guns, but I'd probably use some adaptation of d20 modern.

On point three. While by no means do I claim any level of expertise, I think this might suffice. Imagine a reversed version of how if you traveled a set distance at relativistic speeds, you would arrive having experienced only X years, while your compatriots on earth experience several times that number of years. You don't suddenly experience an expansion of ages just because you slowed down, (at least I'm not aware of anything to suggest that). Similarly, just because the future is now different shouldn't necessarily mean you no longer have memories of that future you came from. Why should the universe you are observing arbitrarily alter your memories?

Worst case scenario, point out that you are playing a game built on many assumptions, physical impossibilities, and gross probability errors (nat 20! I get to suddenly deal twice as much damage as average for no discernible reason!/I can see an outline of an invisible object!) as it is anyway, it's just one more concept to add to the willing suspension of disbelief.

For point four, see my first paragraph.

[L Space]

RE: Time paradox, I'd frame it not as "preventing this future," but rather the opportunity to prevent an alternate reality from ending up in more-or-less the same future. It strikes a balance between doing good (saving a material plane and all of its inhabitants) and personal survival (who wants to live in the nightmarescape that is a 40K future if they could escape to a better time?)

Damn, I was going to suggest this :smallbiggrin:. As an added scene, when they do prevent the cataclysm and the timelines are splitting (a rather chaotic event) give them the option of either:
1) Continuing with the present non-cataclysmic world, trying to protect it from further disasters.
2) Or travel back to the cataclysm timeline, where they may be able to help bring a level of stability/safety to the people.

[Uzgul]

RE: Time paradox, I'd frame it not as "preventing this future," but rather the opportunity to prevent an alternate reality from ending up in more-or-less the same future. It strikes a balance between doing good (saving a material plane and all of its inhabitants) and personal survival (who wants to live in the nightmarescape that is a 40K future if they could escape to a better time?)
That reminds me of the multiple timelines approach often used in Star Gate. That might actually work. Thanks


Sorry, all I can think about is how the characters of your players will adapt to the knowledge that everyone they knew and loved outside of the party is now dead and possibly lead a full life without them (course I don't know the backstories so I'm assuming).

Time travel is very complicated. Solving the catastrophe would have the party cease to exist because they never entered that world after hell due to that world not existing. And if they never entered that world, then they never learned of the catastrophe and never went to stop it. It wasn't stopped so the...this is why I hate time travel.
The party consists mostly of murder hobos, that don't care about many NPCs.


If technology can advance, so can magic.

Give the martials better weapons; light sabers or whatever. Reflective armor that bounces energy attacks back a la the carapace of the Tarrasque. Soup those boys & girls up.

Then: drop every spell by one level and turn the level 1 spells into cantrips. Homebrew some new level 9 spells.

You'll still need to guard against abuse of Wish and True Polymorph and the like, while providing even nicer stuff for the new 9th. It's a challenge, but probably easier than inventing a whole new magic system.
That might work, but also might cause more problems than it fixes. Dropping spell levels by one would increase damage only slightly but utility by a tone.


Make sure you address the "why haven't a whole bunch of people fought their way out of hell and made it back the same way" question.
They won't just die and fight their way back to the top. They will take part in gladiator fights with the goal to win their life back. They will have to fight (like everyone else trying) with the risk, that loosing in the lowest rank means becoming a larva (as this will take place in Hades). They actually won't be the only ones getting out that way.


You mention this is all predicated on the notion of a possible TPK. This seems more like the aim of an entire campaign, and not something to pull up as a diversion if the TPK happens. On that note, I'd probably actually just cut to the chase and start the players in hell, and have them be from various time periods. Still, going through only what has been asked.

On point one and two, I think you might be overthinking this from the gamest perspective a little bit. An energy sword might not need to do more damage then a long sword simply because it's energy. I'd treat it more as difference in kind then scale, a longsword which you brought with you out of hell is likely still as useful against common animals as ever, but to hurt people in future armor, you need the energy blade. TLDR; I'd think of energy weapons and future weapons in general as +0 'magic' weapons. This is a little trickier when handling future guns, but I'd probably use some adaptation of d20 modern.

On point three. While by no means do I claim any level of expertise, I think this might suffice. Imagine a reversed version of how if you traveled a set distance at relativistic speeds, you would arrive having experienced only X years, while your compatriots on earth experience several times that number of years. You don't suddenly experience an expansion of ages just because you slowed down, (at least I'm not aware of anything to suggest that). Similarly, just because the future is now different shouldn't necessarily mean you no longer have memories of that future you came from. Why should the universe you are observing arbitrarily alter your memories?

Worst case scenario, point out that you are playing a game built on many assumptions, physical impossibilities, and gross probability errors (nat 20! I get to suddenly deal twice as much damage as average for no discernible reason!/I can see an outline of an invisible object!) as it is anyway, it's just one more concept to add to the willing suspension of disbelief.

For point four, see my first paragraph.
They campaign is already running and they will probably finish the current arc first. At the end of this arc they will be cursed, so their souls will end up in Hades instead of their normal final rest. And nobody said, that the TPK will be an accident. Maybe it will look like it, but it won't be.

1/2: I like that approach. Balancing that will be much easier as old Challenge Rating would at least be partially usefull.

3: I think "because reasons" would work better than that, as all players (including me) have at least some level of expertise in physics. Otherwise that would be easier.
But maybe just saying "because magic" will be the best in this case.


Damn, I was going to suggest this :smallbiggrin:. As an added scene, when they do prevent the cataclysm and the timelines are splitting (a rather chaotic event) give them the option of either:
1) Continuing with the present non-cataclysmic world, trying to protect it from further disasters.
2) Or travel back to the cataclysm timeline, where they may be able to help bring a level of stability/safety to the people.
Now that I think about it, the party will most likely prefer to make the most profit out of the situation...

[Vogonjeltz]

3. I might let them go back to their own time to prevent the (literaly) world shattering event, but I need a way to explain it without creating a time paradox. As I play with a group of physic stundents, they probably won't accept "because reasons".
(If they go back to prevent a future, they have already seen, that future would have never existed to be seen by them, so they would have had no reason to go back)

4. If you have any good ideas, just throw them around.

A couple of ways of looking at it that resolve your issue.

1) Timeline of events is fixed, nothing the players can do actually alters the course of events. Maybe they truly believe that the world shattering event occurred at time X or whatever, but it didn't, it was at time Y, or maybe their going to try and prevent it actually causes it to happen.

2) Timeline of events is fixed. If a player receives a warning from their future selves that would prevent them from providing that same warning, it's fine, that future self was actually from the previous timeline, which chains directly back to the previous point on the timeline and continues from there. In a technical sense, they are further down the timestream than their future self is (because that future self was the previous iteration). This avoids the back to the future silliness of people disappearing.

3) Many-worlds. When the players go back in time, they aren't guaranteed to actually return to their own timeline, and in point of fact almost certainly will not. Going forward in time is fine, but returning to a point in the past virtually guarantees that whatever they saw in the future won't come to pass precisely because the future they saw was dependent on their not existing in the timeline leading up to that future.

i.e. You time travel to the past and bring someone who would have been president to the future. The future you return to is going to be one where that person never became president, because they are with you now, instead of having lived their life. Even if you go back to the exact moment you abducted them and replace them, when you return to the present again, it will now be a present where that person was abducted. i.e. You can never cross the same stream twice.

The time traveler is constant, as are the realities they are switching between. If you go back and stop something from shattering the world...great, but that doesn't actually change the reality you were witnessing, it still exists, everything still sucks there, and so forth, it really just put you on a different pathway where the outcome isn't the one you witnessed. Again, life still sucks for the people stuck there.


Time travel is very complicated. Solving the catastrophe would have the party cease to exist because they never entered that world after hell due to that world not existing. And if they never entered that world, then they never learned of the catastrophe and never went to stop it. It wasn't stopped so the...this is why I hate time travel.

It can be played 3 ways.

1) They can't change the past. Whatever happens, happened.
2) They can change the past, but their timeline is continuous (i.e. Bob starts at point A->B->C, the temporal location of these points is irrelevent).
3) They can change the past, and those changes are retroactive. If Bob shoots his grandfather, Bob winks out of existence OR Bob instantly changes to be someone else who, in the new timeline, developed time travel and for whatever reason killed the person who would have been Bob's grandfather.

By the third method no one would exist who knew a former timeline existed, because everyone's memories would instantly be the 'new' memories that adhered to the new timeline. There's a great short story about this by William Tenn, "Brooklyn Project", wherein an Assistant to the Press Secretary is describing an experiment to some reporters and saying how safe it is, but every time the machine in question travels through time there's a (to the reader only) dramatic change in the state of existence such that by the end the reporters have become slimy bubbles that slither up to examine the machine, and the thing that was formerly the assistant is waving his four tentacles saying 'And as we can all see absolutely nothing has changed!'

For the sake of your sanity, I'd go with the version (#2) where everyone remains staticly aware of their past, regardless of how they manipulate time to result in a new future.

[Aetol]

Re : time-travel. There are several ways it can work.

The "fixed timeline" model, where only stable temporal loops are possible, is not what you want. It makes changing the past impossible.

The "branching timeline" model is what CNagy suggests (I think). In this case, by going back in time you have the opportunity to alter events and steer history in another direction. The original timeline technically still exist, but it can't be accessed by any mean (well, with magic you probably can...). You only have your memories of having been there. Try not to think too hard about how by going back in time you just created an alternate, somewhat better reality (and all its inhabitants) for your personal comfort.

Finally, there is the "single mutable timeline" model, as seen in Back to the Future. Here too you can go back in time and change the past, but the new timeline overwrites the original progressively (it's magic). Unlike Back to the Future though, the changes should not catch up to the time-traveler if you want to make sense : even if the reason to go back in time disappears (which is usually your goal) your time travel keeps having happened.
This means that some time after someone goes back in time, reality is brutally changed to fit the new timeline. Magic and plot convenience should keep the changes to the necessary minimum (i.e. the brutal dictator is now a mildly successful painter, the victims of the regime are alive again, but everybody else is mostly unaffected). It also means that time travel should be very rare (ideally a one-time event) so the timeline isn't rewritten every other Tuesday.

EDIT : ninja'd.

Really, the crux of the problem is that to be narratively satisfactory, time travel shouldn't be expected to preserve causality. Someone steps out of a time machine and kills their grandfather : now they will never be born, but they keep existing in their past. Just because something comes out of a time machine, doesn't mean it'll have to be put in it in the future. From the time traveler's point of view (which is the one you'll adopt) this is all that matters.

[Mara]

Hi, I need some help creating a futuristic homebrew setting with magic.

The plan for my group is, to let them fight their way out of hell (in case of a TPK), but let a few thousand years pass while they are gone. So they will a jump from a medieval to a science fantasy setting. The world will be in a not so bright age after a great catastrophe, that broke the material plane into multiple parts floating in the astral sea (the material plane is an actual plane in this setting).
The technology will be similar to Warhammer 40K. So there will be Chain swords, Energy Hammers, Blasters etc. This way the PCs combat abilities should still be usefull.

So far, so good, here is where I need some help.
1. I will need a lot of homebrew to make this work. So if you know any good source of futuristic homebrew for 5e (in therms equibment other editions might also work), I willl appreciate that.

2. I am not sure how to balance futuristic weapons against magic. An energy blade should do more damage than an ordinary longsword, but that would cause problems balancing it versus caster damage.

3. I might let them go back to their own time to prevent the (literaly) world shattering event, but I need a way to explain it without creating a time paradox. As I play with a group of physic stundents, they probably won't accept "because reasons".
(If they go back to prevent a future, they have already seen, that future would have never existed to be seen by them, so they would have had no reason to go back)

4. If you have any good ideas, just throw them around.
The pathfinder technology guide actually has many examples of future tech weapons. You can convert those to 5e easier than you can make them from scratch.

It's also freely available on the prd.

[Steampunkette]

A: Alternate Timeline. Has the innate Moral Quandry of "Unmaking" every person that existed in the no longer viable timeline. Everyone born, there, no longer exists and will never exist.

B: Time itself is mutable, with no deterministic events due to mystical influence of deities which exist outside of determinism in some way. Same issue with unexistence as previous option, but it becomes irrelevant because the souls still exist and will be placed into a body at some point, only the conditions surrounding the birth change while the immortal self is sacrosanct.

C: Time Travel works in the way that is most convenient for the DM because nobody in reality has any freaking clue how it would -actually- work since it is, for all intents and purposes, impossible.

[Aetol]

C: Time Travel works in the way that is most convenient for the DM because nobody in reality has any freaking clue how it would -actually- work since it is, for all intents and purposes, impossible.

First, there are ways to travel in times according to modern physics. Most of them only allow you to travel in the future, but there are also theoretical "closed timelike curves", basically trajectories through space-time that return to their starting point.

More to the point, even though time travel as depicted in fiction – basically teleporting through time – is not possible, it doesn't mean we can't logically deduce the consequences of it and come up with consistent rules that could govern the timeline's behavior. "It's not possible in real life" absolutely doesn't mean "it doesn't need to make sense".

[Ralanr]

First, there are ways to travel in times according to modern physics. Most of them only allow you to travel in the future, but there are also theoretical "closed timelike curves", basically trajectories through space-time that return to their starting point.

What...:smallconfused:

[Steampunkette]

Moving close to a high mass object in space warps space and time. That means a satellite traveling around the planet exists at a different time scale than on Earth. It's a tiny difference, but it exists. Around a , arger mass, like Jupiter, the difference would be greater. While near a Black Holes Event Horizon, Time essentially stops, for all intents and purposes.

If you could survive the gravity, you'd be transported into the future based on how much perceived time you experienced near the high mass object.

The rest, time curves, are theoretical, not concrete.

Though if an Einstein-Rosenberg Bridge were to be found and stabilized for travel it would theoretically allow for time travel, since time and space are tied together and such a wormhole would require an endpoint to exist within a certain time frame it may be possible to place that time in the past. At least from one perspective.

[snowman87]

Doctor Who addresses this a whole lot. Basically, if you want an exciting story, you need to gloss over pure science and focus on the story.

If you NEED to explain it away, the alternate realities theory is always the best go-to. Going back would create a new reality and nothing would change in the original, but hey, the characters would feel all satisfied and cozy in their new catastrophe-free reality.

Then there is the "undo" option. They've time-traveled, which is a no-no. It has to be reversed. Once they reverse the travel, they can do whatever they want to fix the future because it hasn't happened yet. Anything they bring back from the future would disappear, though. Maybe they'd retain their memories, maybe not.

Then there is the TARDIS idea. Some effect is safe-guarding against paradoxes. Anything goes. This may or may not cause damage to the universe.

Then there is the ironic option. Trying to go back and fix things IS WHAT CAUSED THE CATASTROPHE!

The DMG has a whole table for alternate weapon options, including laser weapons and the like. You can start basing weapons off of those.

[Vogonjeltz]

Basically, if you want an exciting story, you need to gloss over pure science and focus on the story.

If you want a good story it should be internally consistent. Nick Mason (The Weekly Planet) gives a fantastic explanation of why in Episode 8: Best and Worst CBMs of 2013 at 46:33,

"Here's the thing about looper! Look firstly, let's say you really like mystery films, you like whodunits, and you do. And at the end you're watching the whodunit, and at the end of the movie the cop's like and the killer was the butler, and you thought to yourself, the killer couldn't have been the butler because he was in the room with all the other houseguests when the murder was taking place, and you expressed that opinion to someone, and they're like 'You're an idiot! Because that film looked really good, and the actions scenes were really good and it was tense and it was really well acted, so having that opinion, you're an idiot!.' That's looper. Because you'd be like, 'Ok, Looper doesn't make any sense' and they'd be like 'Yeah, but the action's good, and the performances are good, and the special effects are good, so how about you shut up?'....Because I'm expecting a logical conclusion, and there isn't one!"

Anyway, there are literally thousands of exciting time travel stories that are internally consistent, and they are better for it.

[Aetol]

On the other hand, time travel in Back to the Future makes no sense at all, and that doesn't seem to bother anyone.