Intro
With this page I will attempt to document some Minesweeper strategies that I have found through extensive play over the years, as well as some new ones I've found via computer analysis.
There are a fair few Minesweeper strategy pages out on the web, but to me they seem to be sorely lacking in all but the most basic strategies. Typically they teach how to reason out some situations logically, which is good advice, and can help you solve boards with a higher consistency than you used to. But they seem to do a poor job of demonstrating rules of thumb that can be derived from those simple rules.
With the rules listed here you don't have to waste time reasoning out where the mines are; you can instantly know at a glance, just by the configuration of exposed numbers. Some of the basic ones are listed on these pages, that beginners usually notice on their own after a few plays of the game. I have made no particular attempt to be comprehensive, opting instead for useful rules over completeness. I believe there are a number of tips here are not common knowledge, at least judging from what I've seen on other minesweeper strategy websites. I usually play without flagging mines ("NF" in the parlance of regular players) but the rules are applicable whether you flag your mines or not.
Please send along any other tips you may have discovered and I will consider them for inclusion! Any other feedback welcome as well.
How To Use These Pages
I've given each of the rules a stupid name, most of which just evolved in my head over time. I'm open to better suggestions.
Obviously, in every case here, the same rule applies when you see a reflection or rotation of what is depicted. Also, the rules are always good for when you see the "effective" equivalent of a number, as opposed to seeing the "actual" numbers shown here. That is, a known mine in an unrelated adjacent square would reduce a "actual" 2 to an "effective" 1 -- then if the rule is looking for a 1 in that square, it can still be applied. And I've only marked the numbers on cleared squares when they are relevant to the rule in question.
Legend
= safe square that you can clear
= square that you can maybe clear after initial clearance