Short Answer
Crimson Desert is primarily a single-player offline game. After completing the initial installation and downloading the day-one patch, the game can be played entirely offline with no internet connection required.
Internet Required for Setup
An internet connection is required for the initial setup. The physical PS5 disc, for example, requires a roughly 48 GB day-one patch download before the game can be launched. On PC and Xbox, the digital download also includes the patch. Once installation is complete, you can disconnect from the internet and play offline without any issues.
Single-Player Focus
Crimson Desert launched as a fully single-player experience. You play as Kliff and two additional protagonists across a story-driven campaign set on the continent of Pywel. There are no co-op features, competitive modes, or always-online requirements at launch.
Planned Multiplayer
Pearl Abyss discussed a multiplayer mode called Another Journey during early development (2020 to 2021). This mode was described as something similar to GTA Online, where players would create custom characters in a shared world. However, the mode was deprioritized during the game's six-year development cycle. As of launch, Pearl Abyss has given mixed signals about whether multiplayer will ever be developed. Some statements suggest it could happen post-launch depending on demand, while others from the PR team have downplayed the possibility.