Current concepts in writing research primarily focus on monological texts, by which we mean texts that do not demand a reply. But nowadays, dialogical writing – the exchange of messages via e.g. e-mail, text message or internet forum – is increasingly prevalent in private, educational and professional life. We therefore argue that concepts of writing research should also be made applicable to dialogical writing. Based on empirical data from two university e-learning classes, we show how students use communicative routines in order to manage a specific (writing) task: During their group work students face the challenge of initiating new steps and mobilising other group members to proceed with the project. Our study shows that texts accomplishing this task usually follow a three-part structure: They give reasons why writing to the group becomes necessary (“account”), they request the start or continuation of working (“projection”) and they present a personal contribution to the task (“achievement/input”). In cooperative online work, appropriate dialogical writing is a crucial skill. This “dialogical text competence”, as we call it, cannot be taken for granted; indeed it must be taught and practiced as it differs from competences necessary in face-to-face interaction or for writing texts in non-dialogical contexts. We therefore close our paper with a discussion of our results under the aspect of learning and facilitating dialogical text competence in contexts that offer practical experience.