GURPS is an elegant system that models most things well, but one place I find it lacking regards the mechanic for fatigue points. Let me explain.

If you watch a boxing match, the fighters don’t remain engaged for the entire match. They engage; throw punches; back off; circle around; re-engage; clinch, etc. You get the point. And even with all that dallying, by the time they return to their corners between rounds, trainers must wipe the sweat off and re-hydrate. Real people cannot maintain elevated levels of physical confrontation for lengthy periods of time without succumbing to exhaustion.

To simulate this in my games, I employ a house rule according to which combat maneuvers cost fatigue points, extra effort maneuvers cost extra fatigue points, and Evaluate and Do Nothing maneuvers replenish fatigue points. I outline the system below.

Maneuver Costs

Melee FP Cost		Ranged FP Cost
Attack	-1 FP	Attack	-0 FP
All-Out-Attack	-2 FP	All-Out-Attack	-0 FP
Grapple	-1 FP	N/A	N/A
Move	-1 FP	Move	-1 FP
Move and Attack	-2 FP	Move and Attack	-1 FP
Sprint	-2 FP	Sprint	-2 FP
Change Posture	-1/level	Change Posture	-1/level
Fast-Draw	-1 FP	Quick-Readying	-1 FP
Active Defense	-1 FP	Active Defense	-1 FP

Free Maneuvers

Melee Maneuvers	FP Cost	Ranged Maneuvers	FP Cost
Aim	N/A	*Aim	-0 FP
Ready	-0 FP	*Ready	-0 FP
Step	-0 FP	Step	-0 FP
All-Out-Defense	-0 if untriggered; otherwise, each active defense costs -1 FP.	All-Out-Defense	-0 if untriggered; otherwise, each active defense costs -1 FP.
Concentrate	-0 FP	Concentrate	-0 FP
Critical Success	Any maneuver on which you score a critical success costs 0 FPs	Critical Success	Any maneuver on which you score a critical success costs 0 FPs

*Some muscle-powered ranged attacks (e.g., bows) cost FP to ready and to maintain. If so, -1 FP per round of aim.

Recovering Fatigue In-Battle

To better simulate the ebb and flow of a real battle, where participants will break off to catch their breath, players should roll HT at the end of any round where their character took a Do Nothing, Evaluate, or Wait (untriggered) maneuver and did not execute an active defense. On a success, the character recovers his margin of success in fatigue points (minimum 1). Characters with the Fit advantage enjoy a +1 to their HT rolls; players with the Very Fit advantage enjoy +2 to their HT rolls.