Is herpes encephalitis contagious?

Not really: Herpes virus types 1 and 2 are contagious, mainly by direct contact with an infected person's sores. A never-infected person, without protective antibodies, could catch herpes from a patient with herpes encephalitis, but he would likely just get a typical herpes infection and future recurrences of sores. It is very unlikely that he would get herpes encephalitis, because encephalitis is quite rare.

Typically not: Herpes encephalitis is a rare condition- I do not know it to be contagious- it is very serious and needs to be treated aggressively.