Diamonds Club drops you into the heart of 1899 London, where four gemstone magnates battle to turn their rural estates into dazzling palaces of precious stones. The game blends economics, industry, and resource strategy, requiring players to invest in mines, mining rights, and the latest tech of the era. Each turn is split into distinct phases: first, participants place coins on a central board, paying the coin value plus the sum of adjacent coins to unlock mines, ships, or prospecting rights. As more coins are placed, the benefits become pricier, creating a scaling rhythm that tests each player's planning skills.

Once everyone passes, the combinations of mines, ships, and rights can be exchanged for gems, the game's primary currency for buying attractions in the park. These attractions range from forests to zoos, and each combination can earn extra points if you complete certain objectives, such as owning five identical attractions or a specific set. Beyond attractions, players can also invest in technologies that boost gem production, increase the value of certain park pieces, or expand the number of coins available each round. Technologies are organized into tracks, letting players choose strategic paths that align with their park-building plans.

The ultimate goal is to finish the most valuable park before the others. As soon as one player completes their park, the game ends and everyone tallies victory points. The winner is the one with the highest score, combining the value of attractions, tech bonuses, and achievements earned throughout the game. Diamonds Club offers a rich economic decision-making experience, with a pace that can be both relaxed and intense, depending on how much players want to explore the interactions between resources, tech, and park construction.