Chi Power: What can and can't it do?
 

The short answer is that since it isn't real, it can do whatever the GM likes. But I'm asking for your sense of chi. What sort of abilities feel like they should fall under chi and what abilities should generally be impossible with chi?

Re: Chi Power: What can and can't it do?
 

It's essentially a version of psi. And like psi, there are lots of stories where it's extended to do pretty much anything.

Still, it does seem to be a little more focused on your physical body - you might expect that with the root meaning being breath, but then that's the root meaning of spirit too. I'd tend to say that anything that affects only your body or your internal mental processes is fair enough, and anything that affects something more than a few paces from your body is pretty iffy, and that like psi it really ought to be limited to energy levels you could get out of a human body, though stories certainly don't stick to that very strictly.

Re: Chi Power: What can and can't it do?
 

Unfortunately, when I think Chi I think DBZ. In that, there is little Chi can't do. I suppose it cannot resurrect the dead.

If I try to not consider DBZ, I mostly agree with malloyd, but would extend Chi to affecting equipment you wear or carry at all times, as it is an 'extension of your body'. Possibly use a perk per item you can effect with ease, taking 1-2 weeks to change items or gain a new one.

Re: Chi Power: What can and can't it do?
 

Both as a gamer and a writer of game supplements (so you'll see this bias in your GURPS books!), I visualize chi as being to the body/material as psi is to the mind/abstract. To elaborate:

I visualize chi as being vital energy, breath, and life force, generated or tapped by one's mortal vessel. Thus, chi has firm roots in the material world, anchored by flesh and blood. This mostly leads to feats of athleticism: amazing endurance, controlling and holding breath, resistance to injury, and superhuman strength – and for students of a warrior bent, the ability to adapt such things to combat (controlling breath leads to a kiai, resistance to injury hardens a body part to punch through something, and so on). In the hands of the greatest initiates, chi can be projected a short distance away from the body to produce limited telekinesis and various "energy blasts," and the user can sense and manipulate chi in others' bodies to sense life and cause afflictions (up to and including the dreaded Hand of Death). The natural affinity is for the body, usually the user's but occasionally somebody else's.

This is in contrast to psi's psychic energy. Psi emanates instead from the user's abstract, immaterial mind – or, in pre-modern settings, one's immortal spirit. Its home realm isn't the material world of the body but the astral/spiritual one, and it produces unusual effects at a distance by taking shortcuts through that level of existence and impinging on the regular one, explaining clairvoyance, telekinesis, and – for the extremely adept – teleportation. As not just space but also time is mapped differently to this otherworld, psychometry and precognition are possible as well. The natural affinity is for minds, not bodies, so telepathic feats are basic to psi while only the highest-level adepts can manage direct healing or affliction of the body, largely by inducing subtle mind-over-matter effects.

When using both in the same setting, I recommend reserving purely bodily stuff like Breath-Holding, Damage Resistance, Metabolism Control, and Regeneration for chi, and remote sensing and communications like Clairsentience, Mind Reading, Precognition, and Telesend for psi. Either power might have Affliction, Innate Attack, and Telekinesis, but psi-based versions are likely to cause afflictions of the mind, inflict fatigue, have no visible effects, operate over long distances, and be Maledictions whenever possible, while chi-based variants are more likely to deliver afflictions of the body, inflict injury, have visibly energetic effects, be short-ranged, and often be ordinary physical attacks. I'd counsel putting a prerequisite system in effect to better handle overlaps. For instance, both powers might acquire Healing and similar effects, but such things would be basic for chi but advanced for psi; similarly, both might have various kinds of Detect and other remote senses, but these would be basic for psi and advanced for chi. The most impressive feats – like Warp and Jumper for psi, and lethal Afflictions and being Unaging for chi – would be at the very pinnacle of the prerequisite tree.

Re: Chi Power: What can and can't it do?
 

Indeed, I see chi as having mostly buffs (DR, IT:DR, Lizard Climb, Immovable Stance) - and a limited repertoire of attacks (Kiai, Breaking Blow, Modified ST-Based Damage, Imbuements). Save the flashy stuff seen in DBZ and Naruto for psi or over-the-top games. :)

Re: Chi Power: What can and can't it do?
 

How unusual is it to have a world in which chi can buff the character's own senses?

Re: Chi Power: What can and can't it do?
 

I don't think it's without precedent in fiction. I can think of examples of Danger Sense and Acute Hearing/Touch off the top of my head.

Re: Chi Power: What can and can't it do?
 

When people start comparing chi and psionics, I think of the old 2e AD&D psionics, which was a real bag of random things. It was more like "super powers" for a fantasy world than any coherent theme. Also, game mechanically suspect, but that's a separate issue.

The entire "Biokinesis" power or whatever it was called, that let you grow claws and leap like you were under moon gravity, sounds like exactly the kinds of things that should be detached entirely from psi and shoved under chi. With cleaned up SFX, naturally.
Not literally growing claws, for example, but "cutting them with your chi" for the same net combat effect.
Or if you like, you invoke your Tiger Paw technique and really do grow claws. That's getting a little flashy, but what things do is a separate thing from how they look when they do it. I think a game world can totally support chi doing basically low-key things in a dramatic way.

Re: Chi Power: What can and can't it do?
 

Not very . . . Real-life chi-building exercises involve a lot of efforts to increase one's awareness of the immediate environment – and, in martial-arts contexts, to sense movement and intent in the body of one's opponent. If the associated claims were true, you would have a lot of chi users with Danger Sense, Detect (Life), Discriminatory Hearing, Enhanced Tracking, Peripheral Vision, Subsonic Hearing, Sensitive Touch, and Vibration Sense. As I noted upthread, Clairsentience and Precognition would be straying out of idiom, though they might barely fit at the highest levels. Most other superhuman auditory and visual enhancements – like Dark Vision, Infravision, Microscopic Vision, Parabolic Hearing, Penetrating Vision, Scanning Sense, Telescopic Vision, Ultrahearing, and Ultravision – aren't really a good fit. Neither are outright supernatural senses like Medium, Mind Reading, Psychometry, and See Invisible.

Re: Chi Power: What can and can't it do?
 

Some things that I wouldn't let chi do in a super-martial artist game (although I would probably allow other power sources in such a game):

Controlling machines
Reading verbal thoughts (but sensing emotions is fine)
Sustained flight
Turning insubstantial
Teleportation through solid barriers
Long distance teleportation
Actual physical shapeshifting into other species
Creating zombies
Controlling elements
Creating matter
Having visions of future events (but danger sense is fine)