You're right; I was too hasty and only covered half of the solution with Grave Strike. The correct spell is Spark of Life, which will "tenderize" the lich so that it loses its immunity to Fortitude save effects.IcyCool said:As PallidPatience mentioned, even if you cast Gravestrike and got your sneak attack damage, the Lich is immune to effects that allow a fortitude save, so the Death Attack portion of your attack would still fail.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.