[dragonwriter]

Most versions of the "castle doctrine" while they have lower bars than is generally the case for self-defense outside of the home still require more than simple trespass (the term can apply to anything from merely eliminating the duty to retreat when in the home, to doing that plus presuming justification on a lower bar than would otherwise be the case.)

"Stand your ground" laws eliminate the duty to retreat outside the home for self-defense, but don't generally lower the justification threshold.