Strategy is most useful in an instance of interactive conflict where the participants are able to sense the actions and adjust to the actions of their opponent. Also known as Head to Head conflict though at times other nominally static tasks may present and respond best when approached strategically.
Originally Strategic Choices were a trinity and indeed the original three are subsumed wtih the more recent pentacle of choices, These 5 options allow for variable dominance while maintaining a balanced set of choices.
The following is excerpted from Destiny a decision driven roleplaying game that uses it, but conflict pentacle has interesting parrallels already existing in some games and can also be nicely warped to suit others see my combat styles for Ars Magica
Simple/Direct also known as Proactive
this is seen by some as no strategy at all.. but rather an attempt to perfect tha actions and forms of combat itself. While this does involve minor assumptions it is really only in the vaguest way predictive ignoring most deceptions and complexity, it relies somewhat on forcing a quick resolution, it is to the point with little or no wasted effort, the simplest and most basic strategy. Pure acts "without strategy" are effectively Direct.
Responsive/Manipulative
This is the strategy that uses its adversaries action and innaction against itself. These strategies attempt to control the situation by force and by using the visible actions and status of the situation to immediately adjusting your own actions and exploiting them, in most cases it resolves concurrent with your opponents actions and hence matches the speed of the direct proactive maneuvers and when applied against a proactive challenge and defeats it because of the added benefit of analysis. (these actions tend to be of somewhat reduced potency in result inorder to achieve quickness). The reliance on fairly immediate perception of the situation makes this vulnerable to the deceptive and complex challenges.
Deceptive/Complex
Taking an indirect route and hiding true intent behind a layer of complexity or outright hidden intent and so defeat strategies such as responsive maneuvers but their complexities and deceptions get ignored by those taking the direct route and can be figured out... by analytic response. Those acting instinctually cant seem to resist apparent openings left via deception and are defeated by it.
Analytic
This stretegy looks for deceptions analyses the opponents actions.. Adjustments to ones own performance based on a more precise perception of the situation much like reactive but it extends the performance attempting to achieve optimal assuredness at the expense of speed, it over comes many deceptive and/or complex challenges by avoiding reactive conclusions, but is vulnerable wild unplanned action which are not suited to prediction.
Instinctive /Wild /Chaotic
This fast but unplanned barage of action can overwhelm those who try to find its plan... it doesnt have any...It invests little in any given subaction lacks the follow through of direct action and so is cut short by resolute direct action.