“奇”指乙、丙、丁三奇，“门”指休、生、伤、杜、景、死、惊、开八门，“遁甲”则是隐藏甲木之意。奇门遁甲以甲为首，甲藏于六仪之下，通过遁甲变化形成一套时空布局系统。
古人将奇门用于军事布局、治国安邦，现代则用于商业决策、出行择吉、问事决疑等日常场景。
后天八卦与洛书九宫结合，形成固定的空间方位基础。每宫代表一个方向、一种属性与一段时空。
休、生、伤、杜、景、死、惊、开八门代表人事活动的八种模式。生门旺则利求财，开门旺则利开创，伤门旺则利竞技。
天蓬、天任、天冲、天辅、天英、天芮、天柱、天心、天禽九星，代表天时与外在环境的能量状态。
值符、腾蛇、太阴、六合、白虎、玄武、九地、九天，象征冥冥之中的无形助力与隐性风险。
使用时家奇门，先确定所问之事的时间与方位，再观察格局组合：用神落宫的生克制化、门星神的旺衰，决定行动时机与方案选择。好的格局是“吉门吉星吉神同宫”，若凶门凶星夹击，则宜守不宜进。
Often called the "art of the sovereign," Qi Men Dun Jia is one of ancient China's most complex strategic systems. It maps heaven, earth and human factors onto a nine-palace grid, then overlays eight gates, nine stars and eight deities to model the energy of any moment and direction.
The Earth Plate sets the fixed spatial grid based on the Later Heavenly Sequence of the Bagua. The Human Plate adds the Eight Gates — patterns of human action. The Heaven Plate layers the Nine Stars, representing the cosmic climate. The Deity Plate adds the Eight Invisible Forces that influence outcomes behind the scenes.
For practical use, identify the issue, pick a time and direction, then observe which gate-star-deity combinations activate the relevant palace. Favor auspicious combinations; avoid pushing forward when harmful configurations dominate. Beginners often start with the Doors of Opening (career), Living (wealth) and Resting (well-being).