From LSWiki

Class: Combat Skills
Attribute: Constitution
Pedagogy: Physical Training

One with this skill is difficult to faze, his system resistant to shocks.  
The higher this skill, the more difficult one is to stun.  If a shock is 
sufficient to stun, however, its effects will not be reduced.

See Also: Resilience

Trainers

Avalon: Bercilak
Devonshire: Thalask
Kolond: Duthien (only trains dwarves)
Losthaven: Raelan Jax
Mordor: Badlokk
Mycenae: Kyros
Nexus: Goth
Othrys: Ripheus
Quetlatl: Itozuma Wanders
Shadow Tower: Boko
Shatterspire: Sthlar
Stillwater: Captain Roberts
tlaxcala: Axton
Valathyr: Pelanor
Xi Feng Ming: Shun Lang
Association required:
Losthaven Guard: Captain Jonathan Tredwel
Maidens of the Spear:  Sulin
the Stalkers of the Gate: Kalyxes
Guild required:
Aisenshi: Musashi
Battleragers: Borulien
Brute Squad: Fezzik
Hawkmen: Katar
Justicars of Tyr: Edwin
Justicars of Tyr: Strom Thromgald
Knights of the Round Table: Sir Lancelot
Nizari: Hasan Wanders
Ordo Ignis Aeternis: Aedryl 
Ordo Ignis Aeternis: Iklam wanders
Verynvelyrae: Sirinil
Quest required

Notes