Characters have 6 states of health:
Character is perfectly health, or at least as healthy as they ever get. In game terms this might mean that they have old cuts a bruises but nothing that's going to actually hamper their performance.
This is a minor injury or similar, something that will generally get better
soon if the character rests for a while (returning to Fine). Bruises or minor
cuts. This covers injuries which aren't in any way serious or life threatening,
but which DO have a negative impact on the character's abilities. A character
in this state is generally in considerable pain and suffers penalties for all
actions.
An example of this kind of injury might be a cut from a small knife, a well
connected punch or minor injury from falling off a slow moving skateboard.
The next step up is a more serious injury, one which generally won't heal without
medical attention. This seriously reduces the character's effectiveness, but
leaves them functional. Generally speaking, a character in this state who receives
proper medical attention will "heal" to the Bruised status, where
they will remain until they heal properly (either over time or with magical
assistance).
A good example of this might be a deep knife cut, broken limb or small caliber
handgun bullet.
A character who finds him or herself here is really in trouble. They are basically
non-functional but conscious and can usually speak or drag themselves about
slowly and painfully or attempt more complex stuff at severe penalties. This
guy ain't going anywhere in a hurry and he'd better hope he's got mates nearby
to bail him out.
With proper and prompt medical attention, a character in this situation will
rise to Injured and therefore be functional, but impaired until they can heal
properly over time. If a medical attention is not received in a timely fashion,
things tend to get worse and the unattended character will eventually fall unconscious
either from blood loss, shock or pain.
You might get hurt like this by getting shot with a regular handgun, clawed
by a dragon or run over by a car.
As above, but to add insult to injury you're also unconscious. Even worse than
that is the fact that you're badly enough damaged now that it'll take far longer
to heal properly.
This would happen if you were to take a shotgun blast at close range, hit by
a truck or find yourself bleeding a lot after you were Fucked.
It doesn't get much worse than this. If you really have to talk to a character in this state you'd better find a necromancer.
Thing which hurt characters are given the game term Hazards. A hazard might be a weapon, or some other potential cause of injury. Each Hazard has a damage value: the default condition which a character will be in after they came into contact with that Hazard.
For example, Trev has a cosh which he often carries. It's base damage is Injured - by default anyone who gets hit by terry's cosh will be Injured.
The actual state which an attack leaves you in won't necessarily be the default damage value of the Hazard though, there are a number of other factors involved. If it is an attack, then the skill and possibly strength of the attacker could move the final state up or down a notch or two. Also, the ability of the target to avoid being damaged by the Hazard has a similar effect.
Characters with high Physique attributes tend to be harder to injure that those with low Physique. Certain advantages and disadvantages might also affect this. Characters who have high totals in their attack attempts will raise the injury status of their target. As characters receive injuries their ability to defend themselves drops. This means that any subsequent attacks have a higher chance of being raised to higher injury statuses.
For example, while sneaking around in a warehouse, Terry hits someone with his cosh. He has the advantage that he's hitting a sleepy and underpaid security guard and so he's been able to sneak up behind the guy and whack him. The basic damage of Injured is bumped up by Terry's success to Fucked. Since terry also was specifically aiming for the guard's head, that bumps him to Fucked U/C, and he goes down. Since it was a very specific attack with a blunt weapon, there is no bleeding and minimal actual damage. As a result, the guard's condition will not get any worse if he is left alone.
If Terry really wanted to kill the guard, he could hit him again. now Terry also get's a bonus because the guard's not only incapable of defending himself but he's also Fucked. This means Terry would be more likely to get the required 3 extra Injury level's required to actually kill the guard. He could simply keep hitting him again and again until he get's a good enough success to inflict a Fucked Dead result, at which point the guard dies.