“Don’t Kill Your Grandfather”: A “Don’t Rest Your Head” Time Travel Hack

A few years ago I applied for an open call to submit to Don’t Hack This Game, an anthology of hacks for Don’t Rest Your Head, the RPG by Evil Hat Productions. Don’t Rest Your Head is a great horror RPG with a dice mechanic that appeals to my board gamer side: it’s almost a push-your-luck game formed into a story game.

After a bit of time bouncing around, it was announced this week that the anthology project would be shelved, and those of us who had written hacks for the project were encouraged to post them publicly. Here’s my entry: Don’t Kill Your Grandfather, a time travel hack that’s kind of like a dark Quantum Leap.

For more time travel RPG adventures, be sure to check out the Timewatch RPG when it comes out, which also features a piece (though a non-time travel piece) by me.

Don’t Kill Your Grandfather

by Dave Chalker

The allure of time travel was too compelling to ignore. An illegal, bootleg quantum accelerator was supposed to be your ticket to a better life, the key to changing your messed up life for good. However, something went wrong and turned your round-trip ticket to history into an unending journey, drifting throughout time. This is where your story begins.

You Are A Drifter

You are one of a handful of time travelers that have become unstuck in time, drifting to various points in history. Sometimes, you can control where and when you arrive. Other times, you feel an irresistible pull toward a certain moment. It’s in these moments when you have met others in the same predicament. You’re a Drifter.

By concentrating, Drifters move through time… but it’s not as easy as that sounds. You can’t stay in the same time for very long; eventually, a pulling sensation known as “the drift” overtakes a Drifter and deposits him in another time. Most of the time, the drift lasts only a few days. The longest known period a Drifter has “stayed linear” was a few months. Occasionally, a trip lasts only a few seconds, just long enough to witness a single event.

Regardless of intentions, Drifters are agents of change. Some Drifters try to minimize their effects on the timeline by attempting to fit in. Others do whatever they want in the past. This leads to some conflicts among your kind, as of all types are drawn to major events. No matter the philosophy, though, there’s a shared state of existence that only other Drifters can relate to. This bonds you all together, despite any philosophical differences. Even enemies may eventually become allies, changing personal policies of what to do about changing history, in order for a slim chance that it will lead to a way home.

Making Sense Of Paradox

All those different kinds of time travel you saw on Star Trek? They’re real, every one. When the quantum accelerator was first developed, scientists and philosophers attempted to explain it by leaning heavily on the Many-Worlds Interpretation of quantum mechanics. Trips to the past created a new alternate universe, meaning no matter what changes were made, the universe just splits off into a new, divergent timeline.

However, this doesn’t explain Drifters. There are plenty of times when one will make a change in history and creates a new timeline, which he can then go forward and see the consequences of. There are times the actions of a Drifter seemed predestined—changing nothing, and in fact making it seem as if he was always meant to have done what he did. Then there are times when a Drifter makes a change in history, and both timelines become true: the Titanic never sunk, yet the movie about it sinking still came out and all those people both lived and died.

All that Drifters have determined is that nothing is impossible in time travel.

The Questionnaire

This questionnaire replaces the standard one.

My Name Is…

Choose a name for your Drifter.

Think about: Do you use your real name, like Marty McFly? Or an alias, like Clint Eastwood?

Why it matters: Some Drifters use their real names to keep their sense of identity and provide a connection to their own history. Others think it’s safer to always go by an alias in order to minimize ripple effects.

What’s the First Event You Tried to Change?

You paid a large sum of money or did something unsavory to get the chance to alter history. Describe the event that drove you to do that.

Think about: Was it a personal moment, like asking a girl to a dance? Or was it a major event, like trying to call the FBI on to warn them about 9/11?

Why it matters: Whether you’re on a personal journey, attempting a selfish change, or trying to save the world makes a huge difference in both your outlook and what stories will be interesting for you.

What Went Wrong?

Despite your best efforts, something went disastrously wrong when you tried to change the past.

Think about: Was it history asserting itself, rejecting his attempts to change it? Did you screw up? Did another Drifter thwart you? Maybe you made the moment worse?

Why it matters: This is the catalyst event that caused you to become a Drifter. It serves as your introduction in the story and provides a moment that will haunt you for as long as you drifts.

What Do You Miss Most About Your Old Life?

When you stepped into the time machine, you wanted to enact change in your life, but it wasn’t all bad.

Think about: Did you bring a physical object along with you as a reminder of why you were changing history? Was everything crappy except one thing in your life that you now hold onto? Even if your time jump hadn’t gone wrong, would you still have regretted making the change?

Why it matters: Being a Drifter can seem hopeless, but having something to hang onto can give you something to tether yourself, and means that you have something to return to instead of being forever lost.

How Far Would You Go to Return Home?

There are rumors of Drifters who have been able to stop drifting, yet no one is sure at what cost.

Think about: Will you try and alter the course of history, hoping that you’ll undo the event that caused you to be sent back? Will you try and preserve history as you know it, viewing your trip as divinely guided to eventually be rewarded? If given the chance to save millions of lives who died long before you were born, would you take it?

Why it matters: The promise of finding a way to stop drifting drives most Drifters. How you react when arriving in new time periods, and what your style is about historical events, determine what you’re willing to experience in the hopes of returning home.

Rules Changes

The rules for Don’t Kill Your Grandfather are largely the same as Don’t Rest Your Head, with the dice pools changed to fit Drifters.

Dice Pools

The dice pools change names as follows. Unless otherwise noted, they use the rules for the dice pools they are based on.

Continuity replaces discipline. When continuity dominates, your actions fit into a pre-existing timeline of events that continue the narrative of history with few consequences. Narrate how your action was meant to happen.

Ripple replaces exhaustion, also known as the Butterfly Effect. When ripple dominates, your actions have caused unintended consequences with farther reach than you could have expected. Narrate the larger consequences of your action and increase your ripple dice by one. If you crash, your effect on the timeline has ripped you violently away. You’ll clear the response boxes like normal, and get rid of all exhaustion dice. You’ll drift to some time period where your actions cannot affect the current events, and the consequences of your actions will kick into overdrive. The other drifters might be able to still work within the current time period, but you definitely caused some damage. Eventually, the drifter can return to that time, based on the GM’s discretion, and witness the damage the drifter has wrought.

Paradox replaces madness. When paradox dominates, your actions have broken the chain of cause and effect, leading to unanswerable questions and a nonsensical reality. Narrate how your actions have succeeded, but also how those results don’t mesh with what has already been established. Check off one of your paradox responses and narrate accordingly. When you snap, you’re becoming more a creature of paradox. The permanent paradox die means you’re never able to fully integrate back into any time, even your own. If your continuity drops to zero, you’re now fully disconnected from reality. If you’re lucky, you just never existed. Otherwise, you become the kind of disjointed creature of nonsense other drifters tell stories about. In either case, you’re gone from the game.

Tragedy replaces pain. When tragedy dominates, you have witnessed some terrible event. You might still be successful in what you were trying to do, but there was terrible unexpected fallout that you will never forget.

Paradox Responses

Paradox responses work the same as madness responses. When confronted with paradox, there are two options: fight or flight. A Drifter that chooses to fight doesn’t give up in the face of a break in reality, instead choosing to remain to try to fix things by making even more changes. Flight, on the other hand, implies that the Drifter is afraid to do any more damage to the timeline, and instead runs away before things go worse—sometimes by slipping away to another time, sometimes by just leaving the situation.

Ripple Talents

Ripple talents replace exhaustion talents, in flavor only. Drifters come from all walks of life, and have all learned to use their talents in different ways. Choose one talent related to traveling where the protagonist excels.

Sample Ripple Talents

Cultural Relativist: You blend quickly and easily to other cultures.

Danger Sense: You know exactly when to drift away to avoid danger.

Polyglot: You easily pick up on how to communicate with natives of the time period.

Many exhaustion talents from the core rules may also be appropriate.

Paradox Talents

Visiting yourself in the past may not be an unusual occurrence for you, depending on your personal style. However, one time was clearly important, if cryptic. What did the future self tell you, that you know some day need to know?

This question becomes your paradox talent, which replaces madness talents. You must include paradox dice in your roll to use, and you may break the chain of cause and effect in some way that relates to the prophecy that you have been told.

Sample Paradox Talents

“Beware the man with a blue shirt.” You can declare that someone who is trying to do you harm is wearing a blue shirt, and thus, you were ready to avoid him. At 1-2 paradox dice, this is someone in your way who is a minor obstruction. At 3-4 paradox dice, this is someone pointing a gun at you. At 5-6 paradox dice, someone you have never met (or hasn’t even been born yet) will wear a blue shirt and do something to harm you, allowing a fairly major change in reality.

“You know what he fears.” You can declare a fear or phobia of someone you encounter. At 1-2 paradox dice, the fear is disconcerting but not crippling. At 3-4 paradox, the phobia is significant in your target, but you will need to work in order to find something to trigger the phobia. At 5-6 paradox, the fear something you’re able to capitalize on immediately and cause intense panic.

Many madness talents also work, with slight or no changes. For example:

“Remember that time in the Boy Scouts?” You are prepared at all times, no matter how obscure the item is you need. This is the same as the Preparedness Madness talent on page 27 of Don’t Rest Your Head.

Despair and Hope

Mechanically, the coins of despair and hope work the same as the core game. But they each have a different theme. Coins of despair represent the feeling that you will never be able to escape from this life, and that no matter what you try to change, it will never be enough. Coins of hope, on the other hand, show you that you really can make a difference in history for the better. It’s the continual hint that they are traveling for a reason, and one day, will escape this life having made a positive change.

The Journal

The Drifter’s journal replaces scars. This is a list of where and when the Drifter has been, and what changes he has made, in the hopes of holding onto a personal sense of reality.

Running A Time Travel Game

Don’t Kill Your Grandfather focuses on the consequences of action, and about making a new messed-up timeline. This is a game about people mucking about in history, going back in time to meet themselves, or trying to cheat causality by skipping ahead.

To get started, just pick an event in history that you happen to be fond of. The Drifters might arrive and either see the historical event divert in an unexpected way or might be involved in accidentally changing it themselves.. Remember, Drifters tend to change history just by being around. (Doctor Who episodes often follow this model: just by being there, even when trying to keep a low profile, the protagonists get wrapped up in the events and have to fix them before leaving.) From there, it’s a matter of letting the dice drive the story based on how their actions go.

Another source to draw from are Quantum Leap episodes, where it’s clear that something has to be fixed, but the heroes don’t necessarily know what it is until they get their bearings. Start by drawing the Drifters into the story by making use of the answers on their questionnaires, to give the events a bit of deja vu to their own situations. Toss in some antagonists: they might be natives who don’t understand what the Drifters are but want them stopped anyway, they might be other time travelers working cross-purposes, or it might be reality itself working through coincidence to oppose them. The scariest kind of antagonist, one that all Drifters fear, is a Drifter gone mad—one whose unchecked time travel threatens continuity all over. These Drifters are practically walking paradoxes, and are closest to Nightmares from Don’t Rest Your Head, and can be adapted if you want some especially bizarre antagonists.

You’ll also be inflicting tragedy upon the Drifters as a result. Tragedy is a measure of how much damage a force can do both on the timeline and the Drifters’ sense of hope- or on the Drifter’s person. If the Drifter needs to talk his way out of being dragged in by a guard in ancient Rome, that’s one Tragedy die: not necessarily difficult, and the consequences on history are likely minor whether it passes or fails. Preventing the assassination of Julius Caesar by fighting off all of his attackers would be at least four Tragedy, as it both represents extreme difficulty, an opposition to established history, and far-reaching consequences for the future. Using knowledge from the future (and a hell of a lot of time travel) to try and prevent Pompeii from erupting early might go up to ten Tragedy to accomplish quickly, given how complex the task would be, and how paradoxical the resultant timeline would be.

Just witnessing these events as they are supposed to play out does not necessarily cause Tragedy. Trying to save an ancient soothsayer from the volcano who seems to have insight on how the Drifters can become unstuck is where Tragedy comes into play.

The standard arc of a Don’t Kill Your Grandfather campaign is to move from time period to time period, getting hints that the next drift might be the one that returns the Drifters home for good. Piecing each drift together into one master plan for how to resolve it, be it one “perfect timeline” coming together, preventing time machines from every coming into existence, or even some kind of higher power being what guides the drift, are all options. In any case, at the end of a session, the Drifters won’t necessarily have put everything back in the timeline, and that’s okay. It just has to be intact enough for them to keep drifting and searching.

About Dave

Dave "The Game" Chalker is the Editor-in-Chief and Co-Founder of Critical Hits. Since 2005, he has been bringing readers game news and advice, as well as editing nearly everything published here. He is the designer of the Origins Award-winning Get Bit!, a freelance designer and developer, son of a science fiction author, and a Master of Arts. He lives in MD with e, their three dogs, and two cats.


  1. […] (As discussed previously, the Don’t Hack This Game book for Don’t Rest Your Head was canceled this week. This is another entry from that project by Veredium, covering space horror. –ed) […]