Elden Ring Nightreign allows players to customize their experience before launching the game. While some may prefer playing with others, solo play is an option for those who prefer it.
To start a solo expedition, follow these steps:
1. In the Roundtable Hold hub, approach the table and activate the expedition interface.
2. Select the expedition you’d like to begin, then navigate to the “Matchmaking Setting” tab.
3. Change the “Expedition Type” option from Multiplayer to Single player using your arrow keys.
4. The game will remember this setting, so future expeditions will start as single-player games.
Alternatively, players can play in offline mode by accessing the System settings and changing the “Network” setting to “Play offline.”
If you try to launch a multiplayer expedition while offline, the game will warn you of this limitation.
Source: https://en.bandainamcoent.eu/elden-ring/news/how-play-elden-ring-nightreign-solo-player