While idly perusing some Numenera supplements, I settled in to read Into the Outside. Found an artifact that I figured some of you might get a kick of.
Since there's no kill quite like overkill, I'd like to present the Existence Knife, an artifact that is level 10 (4 above max) and has a blade on it. You decide this dude needs to die. Not only do you want him to die but you want his line to end before it started. If the dude you stabbed isn't of a higher level than [max_level+4], the knife does timey wimey stuff and stabs one of his ancestors instead. You're in the year a billion. I know humans weren't around for the entirety of that, but there are still a gaggle of ancestors to choose from. Better hope it doesn't accidentally snag genetic Adam or Eve. Better also hope you're not distant relatives.
Consequences For Fucking With TimeFailure1. Your skin and organs oscillate wildly on the edge of nonexistence before the timestream adapts, doing 4d10 cosmic damage.
2. Time travel isn't actually possible. The
Existence Knife explodes in your hand, doing 4d8 force damage. You forget about the
Existence Knife. Everybody forgets about the
Existence Knife. Everybody remembering a scene involving the
Existence Knife remembers it with a blind spot shaped like the
Existence Knife. You have no idea why you got blown up and everyone is very confused. Cut the
Existence Knife out of your character sheet with a real knife.
3. You stab yourself in the future. Take normal damage from the
Existence Knife at a time of the GM's choosing.
4. DO NOT MESS WITH TIME. You appear and steal the
Existence Knife out of your own hands before vanishing. That was a close one. You will regain the knife only when you reach this part of your repaired future.
Critical Failure1. Eyes are too complex to have been created by evolution. You now have no eyes, including any indication that you could have had eyes. Lose all vision and darkvision, gain 10ft of blindsight.
2. The mitochondria is the powerhouse of your mom. Your mitochondrial DNA has lost several important adaptations, reducing their ability to safely create energy for your body. Gain three temporary and one permanent levels of exhaustion.
3. Curse of the
Existence Knife. The
Existence Knife disappears and is replaced by an entirely normal knife. You vaguely remember that this is not the true
Existence Knife. What you posses now is the Nonexistence Knife, a quantum necessity created by the timestream. Attacks with the Nonexistence Knife deal 0d4 damage. When you die, the
Existence Knife appears with you in your grave, sending out subtle psychic pulses to your nearest blood relative. This continues for each generation. Every generation after you takes a cumulative -1 to timestream checks caused by the
Existence Knife.4. I'm not saying it was aliens, but... Your actions have placed the Earth under the reign of an oppressive but distant alien species instead of the far preferable period of chaotic human rule you used to be in. Future uses of any artifact above level 3 will incur an orbital strike from your new masters.
Critical Success1. Artificial selection? You feel...different. All human-descendant creatures gain two free attribute points.
2. What is this, fan-fiction? Erase a past tragedy of the player's choosing. This may be personal or collective in nature. The timestream will make minimal necessary adaptations to this change.
3. After getting stabbed, I realized how petty my life was. Instead of dying, the target of your attack becomes deeply sympathetic to your motives and feelings, and vice-versa. Though not strictly compulsive, killing each other at this point would probably be emotionally traumatizing.
4. Your preferences have been updated and saved. The
Existence Knife exits the experimental mode it has been in for the past five hundred thousand years and reactivates its standard safeties. Future uses of the
Existence Knife only stab back a couple of hundred years, removing all results on this table but Failures 3 and 4.