Various modern studies provide excellent evidence that many injuries have little to no cumulative effect outside blood loss.
This is at complete odds with how Hero System treats body damage. According to the normal rules, a dozen nicks is immediately life threatening- and that is without using the bleeding rules.
In order to achieve a closer match to reality, while retaining the favor of high adventure that I desired, I use the following rules in my campaigns:
Hit Location (page 276) is always used for Killing Attacks with the following changes:
There is no cumulative Body damage. All injuries to each location are tracked separately and never added.
Exception- The Automation Power "Takes No Stun", Body remains cumulative if this power is used.
There are no x1/2 body results. Change them to x1.
Hit Location does not modify damage for normal damage attacks. Ignore the N STUN column.
Any hit location taking double the character's body in a single hit is destroyed. This will instantly kill a character if hit in a vital location.
Use Impairing and Disabling rule sections (page 278).
Use the Placed Shots rule (page 277).
Normal Attacks will generally use the Sectional Defenses rule on page 278.
If a Normal Attack ends up doing enough body after defenses to impair or disable, roll the hit location to determine the body part affected.
Use Knockdown and Bleeding rules. Use Knockback in a Superhero setting.
Bleeding Change: Track total damage from bleeding. If total blood loss equals the character's body, he has bleed to death.
The automatic body lost rule (1 body per turn if total body damage equals the character's Body) is replaced by the bleeding rules.
These rules cause significant changes in how lethal Hero System is with a final result between the standard rules and the standard rules with all the 'gritty options'.