Mental Health is used identically to Life Points and can be suffer "hits" in much the same way, from exposure to traumatic and/or horrific experiences. In most cases such exposure is no more dangerous than an equivalent harmless physical assault. Being thumped on the nose or grappled and held causes no damage to Life Points. Being threatened or witnessing a fist fight causes no Mental Health damage either. In some cases a truly horrifying or shockingly alien experience can cause Mental Health damage. Witnessing a brutal murder or even the result of such a murder can cause some (who aren't desensitized to it) to lose Mental Health points.
Mental Health is determined similarly to Life Points, using Willpower and Intelligence. A character with Willpower of D6 and Intelligence of D10 has 16 Mental Health.
Most cases of "damage" to Mental Health result from a Willpower check to resist the effect. Typically this will result in Basic Mental Health damage in much the same way as Basic damage I determined toward Life Points. There are rarely modifiers to this damage but they can occur. Unless there are specific modifiers to the damage or a dice value assigned as further damage imposed on failed checks, Mental Health damage is split evenly between Stress and Traumatic damage with Stress taking the extra point in cases of odd results. Similarly to other forms of damage the GM may rule a preponderance of Stress or Traumatic in some cases but these should prove the rare exception. Likewise few incidents will require additional dice in either Stress or Traumatic damage. This will only be in those rare cases where the horror itself is such that it mimics the trauma being wielded as a weapon in an direct attack on the psyche and will represent only the rare instance where this skill is honed to a practically artistic degree.
Example: John Doe witnesses a violent murder and the GM determines this requires an Average Willpower check to avoid taking Mental Health damage. If John Doe succeeds in the check he doesn't suffer any Mental Health damage. He may also desensitize to similar instances in cases of Extraordinary Success (see below). If he fails however he suffers damage. In this case Basic Mental Health damage is split evenly between two realms of Mental Health, just as Basic damage is split between Stun and Wound points. For Mental Health this is referred to as Stress and Trauma, each being the psychic counterpart to Stun and Wound damage. If John Doe fails the check by 5 points he then suffers 3 Stress damage and 2 Traumatic damage.
Damage Penalties for Mental Health: Depression When the overall total Mental Health damage brings a character below half of their total Mental Health points the character becomes Depressed. All actions requiring any motivation whatsoever, independent of life-threatening situations, suffer a -2 skill step penalty. This should be roleplayed as well and Plot Points will be award as if it were a standard Complication. It is, after all, a temporary Complication. To illustrate: If John Doe has 12 total Mental Health points and suffer a total of 7 Basic Mental Health damage he is now at 4 Stress/3 Traumatic damage to his Mental Health and is Depressed. This does not normally effect combat skill checks (as these typically represent a response to threat) or many other skill/attribute checks (Get Out Of Harm's Way checks, for example). He will suffer a -2 Skill step penalty to all other checks requiring any motivation at all, such as driving, climbing and mechanics. All such non-life threatening tasks suffer from Depression. Damage Penalties for Mental Health: Numbness, Catatonia and Madness When a character is reduced to 0 or less in Mental Health from damage they become either Numb or Mad. In most standard cases the GM will rule whether the form of Madness is some form of mild Catatonia. This will be the standard case although in some instances, depending on inherent circumstances, the form of Madness can largely be anything, typically some form of maniacal obsessive behavior. Numb is near Catatonia for roleplaying purposes and carries a -3 Skill step penalty. Catatonia renders the character unable to respond at all, even to direct threats. That character is out of player control until the Mental Health damage is treated or recovered above the 0 total. Additional Mental Health damage to those already reduced below 0 may also result in cumulative effects, as the GM determines.
New Complications as a result of Madness An Extraordinary Failure (a check that fails by more than 7) may result in the character suffering either standard Madness or taking on a new Complication. In some cases, as determined by the GM, both. Examples are (obviously) Paranoid, Anger Issues, Combat Paralysis and Unstable. The GM imposing new complications should be rare and will only occur in instances of Extraordinary Failure. Characters may use such instance to voluntarily take on an appropriate new complication if they wish.
Recovering Stress damage Like Stun damage, Stress can be alleviated by taking a daily Second Wind as described. Stress is also shed naturally at a rate of 2 points per hour at rest in any peaceful environment, 1 point per hour of activity (light or not) in any peaceful environment. Recovering Traumatic damage Traumatic damage heals much more slowly and requires a full day's rest in a peaceful environment for 1 point of recovery. Traumatic damage is extremely difficult to recover from.
Medication Characters can be given or voluntarily take sedatives in order to temporarily lessen the effects of Mental Health damage, healing d2 to d12 Stress and Traumatic (each, depending on the sedative and the dose). This damage returns when the sedative wears off and damage does not heal naturally nor can Second Wind be taken during this time (the sedative interferes with natural recovery in this case). Sedatives should be taken with caution as the normal penalties for Sedatives still apply and may well render their use counterproductive in most cases.
Second Wind Stress can be alleviated with it's own once daily Second Wind in much the same manner Stun damage can. The PC's can use either Willpower or Intelligence attribute dice for this roll. Player Characters can thus make one Stun damage Second Wind roll per day and one Stress damage Second wind per day.
Mental Health Intervention In some cases other characters can actively treat the Mental Health of other characters. Typically this will result from Faith and So Say We All asset in use. In some cases skills may be brought to use, such as Knowledge/Psychology, Knowledge/Religion and Influence/Persuasion. The difficulties involved will depend largely on the specific asset/skill and their proposed use. Success in such areas typically results in immediate reduction in both Stress and Traumatic damage with a free Second Wind roll to both Stress and Trauma damage. NPC's are able to partake of this type of treatment despite not normally having access to Second Wind. In all cases this is limited to once per day and usually requires a peaceful environment or at the very least relatively safe conditions. Examples: A character with the Faith asset may minister to other characters of the same Faith. A character with Knowledge/Psychotherapy can counsel willing characters. A character with So Say We All can give a rousing speech to a group of followers or provide direct support to an individual.
Desensitization Extraordinary Successes in Willpower checks to avoid Mental Health damage typically result in desensitization to that particular trauma. Witnessing a violent murder for example renders one better capable of witnessing other violent murders in the future without suffering stress or trauma. In all such cases the character receives a +2 Attribute check bonus to such Willpower checks. Two such Extraordinary Successes will typically render such characters immune to the effect completely. However it is always possible to witness, in this example, a violent murder so unusually brutal that it still requires a Willpower check and likely with a higher difficulty. This should prove rare, however. The onus in on the players to keep track of their character's desensitizations. I won't be showing much mercy to those that don't.