It's time to prepare teachers to take the plunge to teach in virtual worlds. Students are already there and their teachers need to follow. Unfortunately, teachers are often resistant to change their teaching practice, especially regarding the use of Information and Communication Technology (ICT) such as virtual worlds. The authors report on the experience of a cohort of pre-service teachers who transitioned from resistance to advocacy as a consequence of immersion in a curriculum-based virtual world. Curriculum-based interactive multi-user virtual worlds contribute to learning through transformational play combining learning, playing and helping. Learners make informed decisions whilst immersed in play. A recommended virtual world is Quest Atlantis; research-based and designed for learners aged nine to sixteen. Importantly, teachers need to be convinced that teaching objectives can be met in virtual worlds. Use of the Technological Pedagogical Content Knowledges (TPACK) framework can provide such evidence. Most Significant Change Stories gathered from pre-service teachers show the pre-service teachers transforming from resistance to advocacy. Findings indicated that once the pre-service teachers experienced transformational play they realised the value of the use of virtual worlds in teaching and that play can support learning and meet teaching objectives. (Contains 1 figure.)