Naturally, Orchestra sets up opportunities for characters to fail, but without Health and Stamina they would have no disincentives to fail- Health is needed to survive and Stamina is needed to keep going, and running out of either in the middle of a mission can be a death sentence.
Health and Stamina:
Health and Stamina are irrevocably linked. The two can be very similar but also incredibly different.
Starting with the similarities, each is derived in the same way. Each skill that a character has specialized (but not double specializations) leads to a one point gain of health, each attribute adds two, and categories add a whopping four. This means that player characters start with 12 health (contacts have 7 off the bat). Running out of either can ruin your day. Neither can exceed 24 by any amount of advancement.
And that's where the similarities end. Health is the essence of life for a character. It's a measure of their physical well being. It's not as mercurial as Stamina. Losing health is a big deal. It doesn't necessarily come with penalties, but it comes with visible, nasty wounds and a threat of potential demise. Even a light loss of health can be visible to a passerby and cause trouble (sharks will come for blood, and the authorities look oddly at people with gaping wounds). When Health hits zero, ambulances are called from all over the place, and negative health is a sure sign of being a dead man. Actual death occurs 6 minutes after zero Health is reached, with each additional point of damage removing one minute. Medical care can restore health and prevent death, though field medicine will usually only prolong death (potentially for more serious care to arrive).
Stamina is the opposite of Health to some degree. It's mercurial, there are few outward signs, and it comes back with a little rest and relaxation (or chemical willpower, but moderation is key). As a general rule, only people who are totally out of Stamina show any effects, and then it's just huffing and puffing and moving with a lethargic undertone. When Stamina hits zero, active use of skills with a potential stamina loss becomes impossible, meaning it'll end a fight. If Stamina goes negative, people get knocked unconscious (Health damage only occurs due to Stamina loss when things like brutal beatings are involved).
Ultimately, all Health and Stamina loss is at the GM's discretion- falling from a building could just wind a person, cause a traumatic leg injury, or cause critical physical trauma. Combat health loss is relatively static, as is the stamina loss from actions, but the GM may decide that certain things are unwise and come up with his consequences.
Fortunately, Health and Stamina are not just measurements of a distance to death and exhaustion, but also a measurement of a character's well-being and energy. Both can be recovered relatively simply.
Injuries to Health are slow to heal without expensive hospitalization. The Medicine skill can be used to prevent death and help prepare for recovery, but the human body's healing capacity is still the most complex and effective method of getting a patient back on their feet.
Medicine can restore a number of Health points equal to one fifth of the result (half without an appropriate kit), but these are ''temporary health'' (noted on a character sheet as such by using a partial mark, special counters, or parenthetical delineation). It can be spent like a normal health point to stave off death (normal health is subtracted first, then temporary health), but it does not count towards eventual healing. This means that a character is mechanically better, but still takes a while to heal from whatever trauma was originally inflicted. Only the best result counts towards a character's temporary health count, and he cannot have temporary health applied outside of the scenario he took injuries in (except with the GM's approval).
Health is restored at a rate of one point per week, plus one for every 500 CCredits spent explicitly on medical care (the maximum restoration rate is four points a week). As a general rule, Health will not be restored (except for temporary health) during a Scenario sans cutting-edge tech or a time lapse.
Stamina is restored at a arbitrary rate of two points per Scene (at the GM's discretion), reflecting the time that characters have to steel themselves. Should players need more stamina, there are items and implants available (some of which are more potent, illegal, or expensive than others) to grant more, with or without strings attached. Any downtime will grant a full stamina recovery, unless the GM explicitly states otherwise.
One point of Stamina is lost for every failed Red skill action except for Endurance and Resistance, though Weight Lifting follows special rules.