Obviously everyone needs to remember there are racial ways of IP proofing, like playing a warforged or in more extreme cases a Maug/Undead.
Construct type is awesome if your not a warforged:
# No Constitution score.
# Immunity to all mind-affecting effects (charms, compulsions, phantasms, patterns, and morale effects).
# Immunity to poison, sleep effects, paralysis, stunning, disease, death effects, and necromancy effects.
# Not subject to critical hits, nonlethal damage, ability damage, ability drain, fatigue, exhaustion, or energy drain.
# Immunity to any effect that requires a Fortitude save (unless the effect also works on objects, or is harmless).
# Not at risk of death from massive damage. Immediately destroyed when reduced to 0 hit points or less.
# Constructs do not eat, sleep, or breathe.