Biting

The verb biting is a form of melee attack done using Teeth.

It is often called "bite" in 4E, not to be confused with the 3e advantage called Bite which is now depreciated.

By default, biting does thrust-1 crushing damage,^[1] though Fangs and similar can alter this.

Martial Arts changes[]

GURPS Martial Arts page 115 under Teeth introduced new aspects about biting, some beneficial and some nerf.

benefit: an automatic grapple if a bite hits (considered to be a one-handed grapple)
- (GURPS Martial Arts: Technical Grappling would later suggest applying the same Control Points as damage, but this only works if Striking ST and Lifting ST are same)
benefit: Worrying on subsequent turns is possible without needing a roll to hit

drawback: cannot bite the skull if same SM or smaller
drawback: limbs can only be crippled on critical hits, and even then only with 7/13/14 (treat any penetrating damage as major wound) and result 8 (double shock results) on B556
- targeting a "tendon within a limb" (same as joints -3 to hit) is an exception

The drawbacks fade as SM becomes higher than SM of target, and Born Biter can add to SM for this purpose

GURPS Zombies page 108 under "Biting 101" clarified some issues:

When using Move and Attack to bite, the “cannot parry” restriction becomes “cannot dodge
Size Modifier and Reach (p. B402) affects arms, not teeth.
If someone tried and failed to grapple the (zombie’s) head or neck .. then on the (zombie’s) turn immediately following the attempt, the zombie can opt to chomp that person’s hand without the usual -4 to hit.
- Zombies are not given any advantage reflecting this benefit so it could be interpreted as a general rule for all biters.

Z109 further clarifies under "Damage:

Hit Location Warning removes penalty to hit hand with bite if the person the hand belongs to tried any kind of grapple on the neck or head and failed (probably intended only to apply to a grapple using the hand which was targeted, but that wasn't specified)
Defense vs. Bites says only close-combat weapons can be used to parry bites unless a retreat can take the parrier out of close combat
weapons that parry a bite can attack the face (jaw is not specified as an option, despite referencing GURPS Martial Arts in applying a -2 to parry -1 to dodge for grappled foes)
on a Move+Attack the Substitute slam rule applies
like Worrying, bites can only cripple but not dismember body parts when at the same or lesser size.