Immune or Non-immune
99% of the human population is non-immune to the H1N3 novel virus. The remaining 1% are immune. This means that while a single bite from a zombie can be ultimately lethal for a non-immune character, an immune character will not succumb to the virus and perish in that way.
When determining your character’s starting ability scores, use the following method:
Non-Immune: 4d6 – drop the lowest number die
All characters, starting HP is the character’s Constitution score. Every time a character levels up and is awarded new HP, they are as per the d20 Modern rules (ie. Class hit-die + constitution modifier).
Ex. Bob is a level 1 tough hero with an 18 Constitution. At level 1 character creation, he has 18 hit points. When Bob reaches level 2, he would gain 1d10+4 HP.
Death and Dying
Characters suffer the same penalties outlined in the d20 Modern book at 0 HP, but do not die until reaching -X, where X is their constitution score. ex. Bob with an 18 constitution would die at -18 HP rather than -10.