Warcraft III is one of the best RTS games ever created and there are several reasons for the mentioned.
Reign of Chaos is somewhat the same as other RTS games: gathering resources and creating units with the use of them and upgrades are possible of course, making your units stronger and more effective. But this game wouldn't be rated that good, if only the basics are in the game, with no extras. Then, what are the extras which make this game special? The heroes and the special moves. Each civilization has its own three heroes. You begin with one, and further on you get to play with two or three. In the campaign you mostly play with one or two heroes. When playing a custom game or when playing online you are able to control a maximum of three heroes. Each one having their own powers and abilities, which you can choose. Each hero can level up till level ten. You choose which ability to choose or to upgrade. This varies from an aura around the hero, leading to an increase of defense or attack rate in a radius, to summoning temporary creatures which are able to aid you in your battle. But not only the heroes have their special powers, some other units have their own as well. Not as powerful as the heroes', but certainly effective. In contrary with the heroes, the other units cannot level up, but they can be upgraded, so you can still e.g. acquire new abilities.
You begin with a town with resources mostly and you have to gather, food, wood and gold. A gold ne is near your town center, so you can immediately gather gold. Same goes to the wood, since the trees are everywhere, especially around your town. The food controls your inhabitants, by restricting them to a certain amount. The maximum is 90 food, which allows you to create all kinds of units, as long as it stays beneath the 90. When you think you have a sufficient army which is able to defeat enemy units, you can advance. The most important strategy in the game is to level up your hero, since he or she can be a decisive key in battle. So you take your hero everywhere you fight. The hero will level up with each enemy unit it or your units destroys, as long as the hero is in the radius and has participated in the fight. After that it´s just like the classic RTS games. You try to conquer your enemy, by defeating all his units and buildings. Numerous strategies can be used and that´s what´s so unique about this game.
There are two difficulties in the campaign: normal and hard, which keeps you sweet for a long time. And if you don't feel like playing it, just create a custom game and play with or against the AI, or maybe even online. It gets you up in rank and it's fun too... The AI is good as well, it thinks like you do, but sometimes it lacks strategy. It's somewhat the same: attacking you while you are gone, or just straight on. But the AI is sure be better than most of the games in its genre, and especially in the year it came out. It returns with the units when being attacked, when they were sent away and recovering their buildings, use of special powers are not even mentioned. The AI is not perfect, but it is only some steps away from perfection
The graphics in the game are pretty good, you aren't able to zoom into your units, but the are quite detailed. You do see the unit in 3D view when selecting a unit. A round portrait shows itself on the bottom, and you actually see him talk as well. An amazing use of the engine. The graphics in the 3D face aren't extraordinary, but the game is created in 2002, so it is not expected that they deliver us a great game, including awesome graphics. The buildings are enormously detailed as well, so nothing bad can be mentioned there. A feature which should certainly be said are the cut scenes. Amazing how it is introduced and shown. Details are rising to the top, especially for a game released mid 2002. But not only the details are great, so is the sound. Wonderful music, great conversations and the voices are clear. If they are not, subtitles appear, so everything has been researched. Nothing more has to said, since everything has been mentioned in this small paragraph.
It just feels wonderful when having this game in your collection. This game should be in every RTS fan's room. But what is expected from a company like Blizzard. You only expect quality games from them. The price of the game doesn't even compare to what you get. The game offers everything you need, when you are playing a strategy game and the experience you get will be bringing along will be saved in your memory forever.