StoriumEDU (https://storiumedu.com) is an online game that turns reluctant students into motivated writers. A sobering 73% of US K-12 students cannot write at grade-level proficiency. This crucial problem must be addressed if we are to build a more informed and empathetic society, and to prepare the next generation for a changing workplace that will increasingly value 21st-century skills like communication and creativity. StoriumEDU addresses this problem by turning writing exercises into engaging collaborative online games, using unique mechanics that motivate students to improve their writing skills while learning at their own pace.