My simple GURPS Chase and Sneak Rules

During my 7 Misfits GURPS game I ran across some situations that I felt needed to be handled a bit differently than the rules I had access to supported.

I suppose I could have bought GURPS Action but I felt at the time it was simpler to role my own, plus of course its the old school way ;)

Anyway those rules worked very well for me, mathematically gave essentially the same results as more complex rules and were fast in play. I'd use them again any time.

Stealth

To sneak past sentries or patrols, roll stealth. In addition to modifiers for light, cover and terrain use the opponents vision roll modifier.
The opponents vision roll modifier is calculated as if the opponent rolled a vision roll of 10 plus modifiers.
For example
Two decent sentries with a +2 on vision rolls have a base roll of 12. This is "making the opposed roll by two" in GURPS terms to therefore the player must make a Stealth roll with a minus two penalty.

Chases

Chases rolls are made the same way with the caveat that the core used for chases is average of Health and Dexterity or Running Skill minus encumbrance, and other penalties. If the total "chase" calculation is less than 10, the difference is given as a bonus. How long the chase last is based on how many "bands" that is successes are needed.

For example

A moderately (-2) encumbered guard with a DX and HT of 11 has a chase roll of 9. This becomes a +1 bonus so our nimble (DX+HT average 12) thief needs to roll at 13- to get ahead. If he can do this 4 times , he escapes. Otherwise the guard catches up to him.

In Urban environments, the number of tries can be limited and if desired, new tries can be created with an area knowledge roll (hey another alley!) or acrobatics for more Parkour style action.