| Insomnium | Dream caused by physiological circumstances such as overeating; no prognostic value |
| Visum | Dream experienced in the transition between waking and sleeping; no prognostic value |
| Oraculum | Prognostic dream in which a person of authority verbally conveys information about the future |
| Visio | Prognostic dream in which future events are rehearsed in plain sight |
| Somnium | Prognostic dream that reveals future events in symbolic visuals |