can Jumper (Tunnel) cause harm?

[Plane]

B64 talks about it lingering for 3d seconds. I was wondering if you had a large creature (say they're 100 hexes long) slithering through slowly and the portal closed when they were only halfway through: what happens to them? Do they get chopped in half, expelled to their new destination, pushed back to their original destination?

Or maybe I'm wrong assuming you actually do walk through these things over time and it's more of a "I touch it and instantaneously all of me ends up at the destination" so a "halfway" situation never comes up?

If we apply this to Warp though (as Powers allows) with the Hyperjump limitation (B98) then there's a definite time-delay: if for example you're going light-speed (-50%) then if you travel the minimum distance (a light-second) there's a 1-second delay between when you begin your warp and end up at the destination, so that probably applies to a Tunnel too... wouldn't that mean you spend 1 second in the tunnel between destinations?

If it were possible to interrupt a normal Hyperjump I'd assume you stop halfway... so if you were traveling 2 light-seconds and someone Neutralized the warp after 1 second, you'd only have travelled one light-second...

Is that how Tunnel should also work, for simplicity? IE just creates a "if someone touches this they warp/jump too" rather than "literally creates a physical tunnel" ?

Powers 147's Create Gate is a little weird in this respect... it's +40% (gate appears AFTER using Jumper, as opposed to +100% where it appears BEFORE) which is used to give a "must step" to the user (this is built into the +100% so you couldn't select it) but I guess it doesn't really matter WHERE you step except for determining the hex at which the gate appears.

It's also interesting how that also applies to those who use it.

[naloth]

Originally Posted by Plane

B64 talks about it lingering for 3d seconds. I was wondering if you had a large creature (say they're 100 hexes long) slithering through slowly and the portal closed when they were only halfway through: what happens to them? Do they get chopped in half, expelled to their new destination, pushed back to their original destination?

I envision a tunnel as a doorway you can step through, but it's just as viable to say that anything that touches it in an any way gets sent through. In any case, I'd let it be chosen when purchased if it's touch send, push through, or push back. By default it's not an attack, nor does it have any way to do damage, so being chopped in half isn't a worry unless you link it with an innate attack.

Or maybe I'm wrong assuming you actually do walk through these things over time and it's more of a "I touch it and instantaneously all of me ends up at the destination" so a "halfway" situation never comes up?

That's not how it's written, but it sounds like a viable limitation.

[Christopher R. Rice]

It doesn't. If you want to do damage with tunnels then add an appropriate innate attack with linked.

[Anthony]

GURPS lacks a firm rule against powers having rare side effects, so GM call. If allowed to do damage, a reasonable rule of thumb would be to treat it an alternate ability.

[Plane]

This is more along the lines of "I accidentally risk harming myself and my allies" than "I intentionally use this to harm enemies" though.

[Taneli]

This is basically a world-builder's decision. If it's a world-premise that closing portals split things in half, then yes.

[David Johnston2]

Originally Posted by Plane

This is more along the lines of "I accidentally risk harming myself and my allies" than "I intentionally use this to harm enemies" though.

It's far more likely to harm pursuing foes than your allies. For one thing you could in fact keep the tunnel open by just doing it again if, say, you wanted to march an army from Earth to Narnia.

[Pursuivant]

Originally Posted by Plane

This is more along the lines of "I accidentally risk harming myself and my allies" than "I intentionally use this to harm enemies" though.

Sort of the way that gates are portrayed in the "Rick and Morty" cartoons, where opening gates in built-up areas or near other people has the potential to cut people or things in half.

[Varyon]

Originally Posted by naloth

In any case, I'd let it be chosen when purchased if it's touch send, push through, or push back.

My inclination would be to shift in the direction that contains more of the creature/object's mass. If you stick your head through a portal and it closes, you get pushed back; if you're walking through and half your leg is still in the original location when it closes, you get pulled through. If it's undetermined which side has more mass, or if they're equal, roll for it.

Originally Posted by naloth

By default it's not an attack, nor does it have any way to do damage, so being chopped in half isn't a worry unless you link it with an innate attack.

The absolute nature of an "attack" like this makes it difficult to build in GURPS - it doesn't matter if you have a million points of HP and DR and Unbreakable Bones, it will cut your hand off as easily as it would remove the wing of a fly. That implies you'd basically have to build it to have enough damage to completely cut through the most resilient thing in your setting that is able to fit through it (similarly to how "immune to damage" is built as having sufficient DR to reliably take no damage from the strongest attack in your setting), and that's likely to be incredibly expensive.

Of course, if you're willing to do away with the absolute nature of it, you could build it on a more sane budget if it basically does some set amount of cutting damage, and if this fails to sever, the target gets pulled through/pushed out, as above.

Originally Posted by Plane

This is more along the lines of "I accidentally risk harming myself and my allies" than "I intentionally use this to harm enemies" though.

This is something that is readily weaponizable. Even if the portal-maker doesn't have control over when it closes (and you can't force it to close early, by knocking him out, using Neutralize, or similar), you can kill a resilient foe by simply restraining him/her halfway through the portal, or destroy a largely-indestructible MacGuffin in similar fashion ("The Ring cannot be destroyed, Gimli, son of Glóin, by any craft that we here poss-" *Gandalf opens portal* "Oh, right then. Carry on." *roll credits*).

Originally Posted by Aldric

There is also the option that the gate doesn't close until the creature has passed through completely (I think Stargate had something like this) which sounds great for travelling with your friends, until you have a gate in your base and an enemy force invading, and can't close it.

An issue here is that it allows you to keep a portal open indefinitely by simply placing a stick or similar partway through it. And this wasn't in play in Stargate - while I don't recall anyone getting cut in half, I do recall a scene where a retreating Jaffa's staff weapon gets the butt end severed from the closing gate, and also an episode of Stargate: Atlantis where the Puddle Jumper gets stuck halfway through and the characters remaining at the origin have to get it unstuck before the gate closes, which would leave them stranded in the vacuum of space.

[naloth]

Originally Posted by Varyon

The absolute nature of an "attack" like this makes it difficult to build in GURPS - it doesn't matter if you have a million points of HP and DR and Unbreakable Bones, it will cut your hand off as easily as it would remove the wing of a fly.

It's absolute only because it was described that way. Conversely if you described it as doing a few dice of damage while it pushed someone through, chopping them up if the damage was high enough, it's not that absolute any more. There's nothing more absolute about a teleportation attack than invulnerability or the one touch kill. Besides if it's better than any of the campaigns attack abilities it's likely worth whatever cost is being charged.

Of course if the GM wants to provide it, I wouldn't worry about trying to build it as a power. The portal weapon just becomes equipment.