Trial and Error Studio brings world class theatre practitioners together with access specialists and creative technologists to make high-quality, XR drama and documentary that aims to expand the horizons of the narrative form for everyone. Our project involves 1) developing a multimodal narrative format that aims to overcome access barriers by applying principles of universal design to the creation of XR storyworlds. 2) developing training in universal design principles for XR narrative. XR technologies change the relationship between storytellers, their work and their audiences. The creative industries are not well prepared for this change. In film, television and theatre, the physical separation between the screen/stage and audience has historically allowed artists to conceive story content without accommodating audience diversity. Captions, audio description etc. can be added on by access professionals. Accessibility is retrofitted. It is not 'baked in' to the original concept. This approach does not work in location based XR formats (LBXR). LBXR audiences do not sit at a distance from the stage or screen. Audiences are physically present in real-time 'within' the storyworlds. It is very difficult to retrofit accessibility features in LBXR environments. In a growing market for XR experiences, this problem urgently demands a solution. Our universally designed multimodal LBXR narrative format and training initiative has the potential to help address this problem. We consider audience diversity from the outset and create our formats with our audiences. By activating the multimodal sensory capabilities of XR technologies, our format offers audiences an increased range of narratively meaningful, complimentary sensory inputs. This aims to makes the content of XR narrative worlds more perceptible for audiences with varying sensory, physical and cognitive abilities, reducing reliance on hard to achieve bolted-on solutions. Crucially our approach involves increasing audience choice, offering customisable XR experiences that audiences can curate for themselves.