Alright. This is a question I'm putting out to everyone, because personally I don't have an idea what to say.

In the group where I GM, I have a Psyker. What a surprise. But anyways, he asked me a question involving a power.

The way he worded it, is 'if [he] was running, while a person was shooting at him, could he space slip behind him, and cut him in half.' Or something very similiar down to those lines. It got into the questioning or simply too many actions taken a turn and such, but then it moved onto something else.

Now for the actual question...

I implore for your opinion. He asked me if he could slip by people using Space Slip, and specifically asked if it made a sound, or cause any disturbance (other than the stuff dectectable by a psyker in the warp) like heat, or something else. It does not specifically say as so, but, in your opinion, does it?

I'd say it depends ow you treat te power. If you view it as a teleportation, then i'd say yes it makes a rater loud thunderclap due to sudden air displacement. If you view it more as spacial distortion, then no as the rules of space are temporally altered for the psyker and, as such, there's about as much air displacement as there would be in stepping from point A to point B.

I'd say no. You could rule either way, but looking at it from a game balance perspective, there's a good chance that your psyker will find himself either co-located with the target or (possibly worse) directly in front of him, but facing in the wrong direction. In the latter case I'd be tempted to rule that the psyker's turn ends immediately due to disorientation, or alternatively, that the target gets to take an "attack of opportunity" as the psyker's undefended rear end materialises in front of him. Even if you didn't do that, it would be a risky proposition for the psyker, because he's effectively lost the chase and has nowhere to hide.

All that said, I would give the target an awareness check or possibly an intelligence check to avoid being surprised. After all the psyker has just disappeared from right in front of him - that has got to make you suspicious.

Cardinalsin said:

Hehe, when playing Quake that is called a "telefrag".

Even if you interpret Spacial Slip as displacing air... that's not a problem in the vacuum of space.

There is no sound in space, but if you're standing on an object, you can 'hear' sounds transmitted through the surface of the object.

There's three ways I can see this happening:

1) The psyker and a very small area are transported into the warp and then back into the physical universe, this would of course bring some amount of physical matter with the psyker and would produce a sound on leaving and entering the physical universe. This would be caused by the displacement and sudden placement of matter, when leaving creating a vacuum (and a rather loud thunder like sound as molecules move into the former space) and a similar sound upon re-entry with a slight wind burst as matter re-enters for foces other molecules out of the way.

2) Only the psyker is teleported. In this case, the sound of moving in and out of physical reality would still occur, although likely not being as loud or as violent, however there is still the effects of removing matter and re-entering matter into space.

3) The psyker is not moving through the warp at all in order to transport themselves, but is instead creating a spatial distortion similar to a wormhole to move from point A to point B, in which case I imagine there is very little sound or other disturbances, perhaps a very faint sound and a very brief flash of light.

That link there is showing roughly what I imagine it would look like for the first two - the only difference being the size due to that's a massive battleship and this is just a human.

In addition: If he is in vacuum, as in - in actual space, not the physics term, there isn't going to be any sound. There is going to be that air displacement though if he's doing it from inside a ship to outside.