In all the single-player games in the Civ franchise, the human player must win before the AI player(s) do. For some victory conditions, that's straightforward: keep control of your own original capital, in Civ 5 and BERT, for example. In Civ 4, one can monitor the Apostolic Palace votes / UN votes, or which AI has built culture-heavy cities and attack them. In Civ 3, the human player can build the UN and never schedule a vote. In both Civ 3 and Civ 4, taking the AI capital would destroy a spaceship and force the AI player to start over. For BERT, I think that one can see if an AI has built the gate for Emancipation and Promised Land victories. One could fight wars before the gate is built to slow them down before the gate is built, but once the gate *is* built, can it be destroyed? Can the human player tell which AI city is trying to build the Mind Flower wonder, to try for the Transcendence victory? Would a covert agent reveal this? Could I attack that city to stop it establishing a link? How does one defend against an AI winning via Contact? The AI could obtain the Signal from Progenitor ruins, and then have to build the Decode Signal project. If I attack that city, either during construction or after completion, would that work? Next, the AI would have to build the Beacon wonder. Can I tell where it is being built? Can it be interrupted or destroyed?