The present paper offers a fundamental discussion of constituent parameters and relevant issues associated with the concepts of pluricentricity and epicenters. It proposes an explicit division into a weak reading, highlighting the co-existence of national varieties of languages, and a strong one, focusing on influence exerted by some varieties on others. Parameters which constitute epicenters include size and speaker numbers, geographical proximity, intensity of mutual relations, directionality of influence, and attitudinal factors. Methodologically, a fully convincing documentation of epicentral influence would call for diachronic data from both varieties in question, an investigation of detailed usage conditions of forms compared, and a plausible account of the potential for contact - though for now this seems very difficult to achieve. It is suggested that the perspective taken should not only encompass standard varieties and that the weak version of pluricentricity has strong roots in language attitudes and perception rather than production.