The research focused on four drugs: marijuana, LSD, crack cocaine, and heroin. The analysis focused on the concept of "interaction as infiltration," a new interpretation of dramaturgical theory which considers the relationship between the structural (extent of group closure) and qualitative (extent of verbal and nonverbal machination needed to deceive) aspects of role performances. The analysis indicated that the degree of dissembling required to create the believability required to purchase undercover varied according to the drug involved. Moving from marijuana to LSD to crack cocaine to heroin required increasing levels of dissembling. However, variables such as class, race, gender, or any combination of these factors could become barriers to persons wishing to infiltrate a particular group. Thus, skillful dramaturgy is not necessarily all that is needed to overcome closure in any group, including both ordinary social groups and groups of drug offenders. 45 references (Author abstract modified)