Several blocks-based programming tools have recently incorporated real-time collaboration features. Some draft approaches we have seen achieve inter-user consistency by using abstract object-state synchronization libraries, but provide no guarantees that the consistent state accurately reflects the users’ intent, particularly in cases where multiple users perform potentially conflicting edits. This poster/demo presents StarLogo Nova’s design for undo and real-time collaboration, which provides a mechanism for user intent preservation via context-dependent conflict resolution rules. The StarLogo Nova technical approach is presented with a few clarifying examples, followed by a series of multi-user scenarios for consideration and discussion in which the “user-intended” outcomes are not obvious, regardless of the capabilities of the collaboration system.