They follow a trajectory that is oblique. Obliquity describes the process of achieving complex objectives indirectly.

In general, the oblique approaches recognise that complex objectives tend to be imprecisely defined and contain many elements that are not necessarily or obviously compatible with each other, and that we learn about the nature of the objectives and the means of achieving them during a process of experiment and discovery.

The environment— social, commercial, natural— in which we operate changes over time and as we interact with it. Our knowledge of that complex environment is necessarily piecemeal and imperfect. And so objectives are generally best accomplished obliquely rather than directly.

Oblique problem solvers do not evaluate all available alternatives: they make successive choices from a narrow range of options. Effective decision makers are distinguished not so much by the superior extent of their knowledge as by their recognition of its limitations. Problem solving is iterative and adaptive, rather than direct. Good decision makers are not identified by their ability to provide compelling accounts of how they reached their conclusion. The most complex systems come into being, and function, without anyone having knowledge of the whole.

Applied to geopolitical events, or complex businesses, the methods collapsed. These latter problems are best tackled, not by moral algebra, but obliquely: they involve high-level objectives achieved through adaptation and iteration, with constant rebalancing of incompatible and incommensurable components that are imperfectly known but acquired as the process goes on.

Good decision making is oblique because it is iterative and experimental: it constantly adapts as new information, of many kinds, becomes available. Much of that information comes from the process of decision making itself.