Because the concepts in physics and politics are at times very complicated or very abstract, Frayn uses several controlling images to better relate certain ideas to his audience.
• Skiing and Table-Tennis – These two activities are referred to as a pastime of Bohr and Heisenberg's, and both demonstrate the competition between the two (representative of national competition.) They are also used to suggest Heisenberg's speed and recklessness which contrasts Bohr's caution and tediousness.
• Invisible Straight – An anecdote in which Bohr managed to bluff himself in a game of poker by betting on a straight that he thought he had, but he really did not. This principle is applied to nuclear weaponry, suggesting that nations will act differently when they think that an opponent can produce nuclear arms, whether or not the opponent can.
• Cap-Pistols, Land Mines and Nuclear Reactors – These fall into the Toy vs. Weapon theme and once again presents anecdotes of Bohr and Heisenberg's lives. Their fascination in playing with the new toy blinds them to the danger that it poses.
• Bomb – The term "bomb" appears as a literal looming image in many cases, but it is used figuratively in a couple of instances, as if it should be a joke, but with such grave implications that it cannot be found funny. (In example, Heisenberg refers to a "bomb having gone off" in Bohr's head.)
• Christian Reaching for the Life-Buoy – Christian was one of Bohr's sons, who tragically drowned while he and Bohr were out sailing. The phrase "Christian reaches for the life-buoy" appears several times during the play, and every time, the characters seem to hold their breath in the hope that this time, Christian will survive. Bohr had concluded that they would have both drowned had he jumped in to save his son, and this presents an idea of futile heroics, particularly with reference to Heisenberg and what should happen if he were to resist Hitler's rule.
• "Another Draft" – Whenever the characters conclude that an interpretation of their 1941 meeting is incorrect, they call for "another draft."