  We study violations of the Null Energy Condition (NEC) in Quantum Field
Theory (QFT) and their implications. For the first part of the project, we
examine these violations for classes of already known and novel (first
discussed here) QFT states. Next, we discuss the implications of these
violations focusing on the example of Wormhole Traversability. After reviewing
the current literature on the existing restrictions on these violations, we
conjecture that NEC violating states are incompatible with the Semi-Classical
Gravity approximation. We argue that this conjecture provides the only way out
of the problems introduced by the violations of NEC in this regime. Building on
this, we propose a bound that should hold for all QFT states. Finally, we show
that both our conjecture and bound hold for some relevant classes of QFT
states.
