Casement is a Twine 2.x (Sugar Cube) engine that adds popup-oriented gameplay to the SugarCube format. It was designed to create smoother flow within Twine, allowing smaller actions to happen without a passage transition. With Casement, actions such as examining something can be put in a popup window that can display wiki text just like a regular passage. Players can close the popup or interact with links in the popups at their leisure. Casement also adds inventory support, allowing authors to create inventory items that can be collected, examined, and used in a context sensitive way. JSON can also be used to make conversations, which use their own, modal popup window that avoids the main problem with conversation in Twine: large numbers of short passages.

Casement is currently in development and will be updated as time and interest permits. The engine was used to create Sunset Directive. A version of Casement is currently being used to make Veiled (unreleased).

Casement's Github page (opens in a new window). Casement is written in JavaScript and CSS.