Quick answer

The official store description confirms the four-player co-op target, but it does not document the complete solo or AI-teammate behavior. Before starting a solo plan, check the current lobby and mission client, record whether a named solo path is available and test one drop. Do not promise that an AI teammate can replace a human class job without current evidence.

A safe solo check

  1. Open the current mission/lobby flow and note the exact solo option shown.
  2. Record whether the game fills missing slots, supplies AI, or leaves the squad short.
  3. Keep the same class and difficulty for one test mission.
  4. Note which job becomes the bottleneck: damage, control, sustain, revive or positioning.
  5. Use that observation to choose the next class or Specialist experiment.

This approach answers the player’s immediate question without converting a single lobby result into a permanent platform rule.

Choose a job for the empty slot

If you are alone, start from the encounter problem rather than a “best solo class” claim. A class that can control a lane may solve a different problem from one that finishes a priority target. The official page describes distinct class playstyles and tactical abilities; it does not establish a universal solo ranking.

Read Classes and Specialist for class decisions. If the issue is the party platform rather than the mission, use Platforms and Co-op.

Evidence boundary

AI teammate availability, solo scaling, revive behavior, matchmaking fill, difficulty changes and mission restrictions require current-client verification. Steam reviews can reveal that players are asking about solo play, but they cannot prove the behavior for every mode or platform.

Sources

Last verified: September 2, 2026. Recheck the lobby, teammate and scaling behavior after patches.