The Tactical Language and Culture Training System (TLCTS) helps learners acquire basic communicative skills in foreign languages and cultures. Learners acquire communication skills through a combination of interactive lessons and serious games. Artificial intelligence plays multiple roles in this learning environment: to process the learner’s speech, to interpret and evaluate learner actions, to control the response of non-player characters, to generate hints, and to assess the trainee’s mastery of the skills. AI is also used in the authoring process to assist in the generation and validation of lesson content. This article gives an overview of the system, and describes the experience to date in transitioning the system from research prototype into a training system that is in regular use by tens of thousands of users in the United States and elsewhere. Experimental results from field studies are presented, relating learning outcomes, motivational effects, and the role of game-based learning and intelligent tutoring in achieving the learning outcomes.