The Ascension Project
As an adventurer, you have more to worry about than taking damage. You might also have to face long-range bombardments, venomous alien beasts, or the charms of a local girl. Luckily, a tough adventurer can survive these too.
Generally, when you are subject to an unusual form of attack, you get a saving throw to avoid or reduce the effect. Like an attack roll, a saving throw is a d20 roll plus a bonus based on your class, level and an ability score.
A saving throw modifier is: Base save bonus + ability modifier
Saving Throw Types: The different kinds of saving throws are Fortitude, Reflex, Will, and Death.
Fortitude: These saves measure your ability to stand up to physical punishment or attacks against your vitality and health. Apply your Constitution modifier to your Fortitude saving throws. Fortitude saves can be made against attacks or effects such as poison, disease and radiation.
Reflex: These saves test your ability to dodge area attacks. Apply your Dexterity modifier to your Reflex saving throws. Reflex saves can be made against attacks or effects such as pit traps or certain explosives.
Will: These saves reflect your resistance to mental influence. Apply your Wisdom modifier to your Will saving throws. Will saves can be made against certain powers.
Death Saving Throws: Whenever you start your turn with less than 0 hit points, you must make a special saving throw, called a death saving throw, to determine whether you creep closer to death or hang onto life. Unlike other saving throws, this one isn’t tied to any ability score. You are in the hands of fate now, aided only by features that improve your chances of succeeding on a saving throw. Roll a d20: If the roll is 10 or higher, you succeed. Otherwise, you fail. A success or failure has no effect by itself. On your third success, you become stable (see Injury and Death). On your third failure, you die. The successes and failures don’t need to be consecutive; keep track of both until you collect three of a kind. The number of both is reset to zero when you regain any hit points or become stable.
Rolling 1 or 20: When you make a death saving throw and roll a 1 on the d20, it counts as two failures. If you roll a 20 on the d20, you regain 1 hit point.
Damage at 0 Hit Points: If you take any damage while you have 0 hit points, you suffer a death saving throw failure. If the damage is from a critical hit, you suffer two failures instead. If the damage equals or exceeds your hit point maximum, you suffer instant death..
Saving Throw Difficulty: The DC for a save is determined by the attack itself.
Automatic Failures and Successes: A natural 1 on a saving throw is always a failure. A natural 20 is always a success.