Abstract: A vacuum formed, tamper resistant container resists deformation of the sides thereof that might otherwise permit access to contents of the container without removal of the lid. Downward protruding lid features reinforce the wall of the container base, and buttress features included in the rim of the base extend from a base flange diagonally downward and inward to the inner rim of a recessed shelf, thereby resisting downward rotation of the wall beneath the lid protruding features. In embodiments, attachment tabs surrounded by frangible boundaries are incorporated in the lid and attached to the base by living hinges, such that removal of the lid requires breaking of the frangible boundaries and detachment of the lid from the attachment tabs. Pucker elements associated with the attachment tabs can cause the attachment tabs to pivot away from the lid when the attachment tabs are detached from the lid.