There are lots and lots of free strategy games to play, but, you know there was one, lots and lots of them aren't worth your time. You've got to know where to look which is what I’m going to do for you, so don't get discouraged. They are out there just waiting to be played if you just put in a little work up front.
The best source of free strategy games are DOS titles published in the 90's. Using an emulator like
DOSBox
you can run old games on your modern computer. DOSBox is free, easy to install, and simple to use. The developers of DOSBox specifically created this tool to play games, so they’ve taken each time and care to make sure the games work.
So if you are like me you have long since purge you game library of DOS games. Have no fear almost every PC strategy game made for DOS is out there on the internet just waiting for you to download it. The catch is that although these games can not be purchased in stores anymore and their Copyright holders don't offer support it is still technically illegal to download them and play. This is a legal gray area and something of a personal moral decision. As time passes and the copyright holders don't defend their control of the titles they weaken there position and eventually will release it to public domain be default. It is sort of like squatting. Do something long enough or allow something to go on long enough without intervening, then you’ve give that thing away. It is the legal version of, "Actions speak louder than words."
The best and most scrupulous source of old DOS games is
Home of The Underdogs
They’ve been collecting old titles since the late 90’s. I recommend them because they have a large catalog of games but more importantly they don’t offer downloading of games that you can still buy somewhere, are still supported or the copyright holder has asked them not to. The Underdogs is more of museum than web store. It is my opinion you are on the moral high ground downloading and playing these games as long as they are not commercial available. But it is something you have to decide for yourself.
Another source of free strategy games is the web itself. Many web games have been written for playing through the browser. They are typically more spreadsheet than graphics.
Play Free Online Games
is the best catalog of these online free strategy games for the browser. They are divided into two groups: Play Indefinitely and Free, with Option to Pay for Additional Features. Play Indefinitely, means you can play without playing and without a time limit. Free, with Option to Pay for Additional Features, means technically you can play the game without paying for anything, but there are some features and advantages only available to those who play. If you are determined to play for free then you will be at a disadvantage usually because paying players will have more money or better weapons than you. Doesn’t mean you can’t enjoy it, but it will be frustrating at times.
I haven’t included demo’s, or shareware games because generally they have been designed specifically to encourage you to buy the game. So it isn’t really a game just a commercial in disguise. And if it ain’t a game then it can’t be a free game. Free strategy games might become more common in the years to come as piracy has gutted the retail and download industry. Browser technology is also starting to come of age and playing games online, and through the browser with advertising will become the norm.