Same-night reservations at a fully booked three-star are not impossible — they are coordinated through long-standing concierge relationships with the maître d', not through public booking platforms. The relationship pre-exists the request.
What to share in the first message: the date and time window (a 60-minute flex window often makes the difference), the number of guests, dietary preferences if any, and whether the table is for a private occasion. Everything else is handled.
Cities where this layer operates reliably: Milan (Cracco, Cracco Portofino, Da Vittorio, Seta), Paris (Le Cinq, L'Ambroisie, Plénitude), Monte-Carlo (Le Louis XV, Yannick Alléno, Blue Bay), London (Sketch, Core, Hide), Dubai (Zuma, Nobu, La Petite Maison, Em Sherif), Rome (La Pergola, Il Pagliaccio).
Private rooms and the chef's table are coordinated through the same relationship layer — typically 24 to 48 hours' lead time, longer for celebratory occasions requiring custom menus or wine pairings.