Reality Shifting Mechanics

The Main Idea

The main idea of this mechanic is that there are essentially two different worlds; one sort of mirrors the other one with small differences.  (People are different, locations look a bit different, one shop exists but another doesn't in the other one.)  Nathan will run one world while I will run the other.  These two worlds sort of run parallel to each other, and every once in a while "rifts" will open between the two worlds and pull whatever's in there to the other world.  Sometimes unstable portals will open, and very rarely there will be stable portals.  These can draw anything from items to people to entire locations through to the other world.  Another idea can be that they can see events from the other world when the two worlds get a bit too close…

Tears

Tears are random, and would be when the two realities get a bit too close, and one pulls enough at the other that part of the other world gets pulled into the other one.  This can happen randomly and generally can't be predicted.  When one of these happens, roll to see how big the tear is, and what gets pulled through.  Tears can be as large as we need them, but for rolling randomly, use this.  The really large tears can be placed by dms intentionally.  This still needs to be balanced.  Roll 1d6 to see how long the tear lasts.  Note that the tear is one way; you can't return through it.

Generating them should be done in two parts.  First part is during the game.  say, every hour, the dm rolls.  If they roll 1-5, a tear will form nearby.  Roll to see what it may hit.  (assign everything nearby a number, and roll a that number sided die.  Whatever number is rolled gets hit.)  Then have the players roll to see if they notice it's gone.  Perception check at your discretion.

Die roll Effect
1-50 1×1 (Medium)
60-85 2×2 (Large)
85-95 3×3 (Huge)
95-98 4×4 (Gargantuan)
99-100 5×5
Die Roll Effect
1-50 Light Pull; Anything unattended pulled through, anyone caught in the effect has to make a DC 40 will/strength(?) check not to be pulled through.
60-85 Medium Pull: No saving throw.
86-97 Heavy Pull: Can be strong enough to pull structures through?

Unstable Portal

Unstable portals are where the two realities are close enough to allow travel between them, but not so close that it creates tears.  I'm thinking that tears are invisible until you get close enough to them, but the players can have an item to detect them if they need.  The portals are unstable; if enough matter travels through them they destabilize and either disappear or could turn into a tear?  Portals are two way.  Roll a 1d4 to determine how many entities can go through before collapsing.  Not sure if we should allow them to see through to the other side or not, or whether if it's visible in one world it's visible in the other.  

An entity should be defined as one object, or an object and everything attached to it.  so a person and all his equipment counts as one.  A box of weapons counts as one.  One sword counts as one.  Not sure if this is abuseable or not yet.

Windows

Windows are areas where space is unstable.  They can see what's happening in the other reality, but they can't interact with it.  Not sure if we should allow sound to go through or not.  Maybe we can have windows with or without sound.  This can be useful for various puzzles.

Venn Diagram-ness

The idea here is that there will be sections of the world where the two realities overlap in some ways; the players may know that something is in a square but not know what it is (when it's the other party in their reality).  Monster may exist in both realities at once, and have to fight both parties.  So the party will see the monster dodge seemingly nothing.  Parties will drop fireballs, and end up hitting the other party until they see what's going on. Basically they have limited interactions with the other reality.  Maybe they can see each other but can't hear, or hear but can't see.  (Marco Polo anyone?)  We can use this for puzzles.  

Consequences for Traveling

We should perhaps impose some consequences for travelling between realities, to prevent people from abusing this.  (though we can also prevent abuse by tightly controlling the various rifts) 

One idea is to create a condition for traveling through, a type of disorientation.  (Jet lag?)  By travelling through like a tear or by trying to force their way across they become disoriented by going through, because of travelling to a different reality at a different time, plus they're not in their natural reality.  This disorientation could possible temporarily lower stats, or give penalties to certain skills or abilities.  Or they could straight up take damage.  I'm thinking the type of damage should depend on how they went through.  e.g. if they go through a tear, take damage.  If they go through a portal, disorientation.

Another idea is a slingshot effect.  If they find a way to get the entire party over to one side, they have effectively unbalanced the worlds a bit, creating a bit of a vacuum.   Roll a 2D6.  After that many minutes, players start being sent back via slingshot effect.  If they get sent back this way, they take the effects of travel lag.  after the first person is sent across roll 1D6, and that many rounds someone else goes through. Then roll 2D6, and after that many rounds a third person gets sent.  Then things are equal.

Rubber Banding – If all players are in one world, the other one rubber bands to catch up with the first. This allows the DMs to synchronize worlds as well as can impose negative consequences on players that leave one world unoccupied (ie: since no one is there, the warlord manages to destroy the village instead of them protecting it)

Reality Shifting Mechanics

Between Two Worlds marshallw DDragon