Starcraft and Starcraft II are probably the best RTSs in history. I will usually refer to them collectively as Starcraft throughout this article, and probably Brood War (BW) or Starcraft II (WoL) when referencing one in particular.
What makes Starcraft so good?
One of the first things I immediately liked about the original Starcraft was how responsive the units were. Tell them to move, and they moved. It is surprising how many games screw that up; Dawn of War is particularly bad for this, where you can only tell your units a vague area to go to, and must rely on their (idiotic) AI to guide individual units.
Starcraft gives you pretty much perfect control over your units, allowing and even requiring you to position them individually for optimal play.
- Racial Diversity
Starcraft is probably the most diverse RTS out there. It has three genuinely unique races, each with completely unique play styles and strategies. Each of their economies works differently, each aims for different types of engagements, each peaks in power at different points in the game - and above all else, each is balanced.
Even within each race, there are massive opportunities for diversity of play style. You can play aggressively or aim for economy; you can favour a tech-rush strategy, you can aim for mass units and production, or you can catch your opponent off guard with unusual technology and special tactics.
The sheer mind-boggling possibilities of the game speak volumes of the undeniable amount of time and effort that has gone into testing and balancing the game; the elegance of the design and the robustness of its systems.
The subtle brilliance of Starcraft is hidden in its economy. I won't get into the individual race's traits in building and maintaining their economies, rather the resources as a whole.
There are two primary resources: Minerals and Vespene Gas.
Minerals are the primary resource, available in abundance with a high capacity for mining and a relatively low maximum yield (at 1500 per field)
Gas geysers vary from BW to WoL; BW gives one geyser per base with 5000 gas, WoL gives 2500 gas in each of 2 geysers. They have a low variance, and can expected to be mined at a constant rate per base. (By this I mean they achieve worker saturation easily, and it is generally expected that you would max out your gas collection more so than your minerals)
There is also the tertiary resource of Supply, which is created by building the required buildings/overlords with your minerals.
Lower tech units require more minerals and supply, while higher tech units require more gas. Lower tech units are also more mobile, while higher tech units are much stronger but slower. Ultimately, the backbone of your forces is made of minerals, while the muscle is made from gas.
This creates the following economic metagame: early game, you expand regularly and build basic units with your minerals. As the minerals in your starting bases begin to die, you must expand to secure more minerals - however your original gas geysers are not expired yet, giving you proportionally more gas, which fits right in with your plans of advancing to higher tech.
You start off quite far from your opponent, which fits that the earlier units should be faster; however, as the game advances, your bases creep slowly towards each other as you expand over the map. The game then shifts towards a battle of positioning, with the slow late-game units besieging the more exposed enemy positions (as you get more bases, it gives you more area to defend, with slower units to defend it).
Seeing it explained like that, can you help but appreciate the brilliance of Starcraft's design? None of that is explicitly stated or coded anywhere, however, because of the incredibly clever way the game was put together, that metagame has shaped the way that people play Starcraft.
- The Races
I won't actually get into the races themselves, but I want to comment on how perfect 3 is for the number of races in an RTS.
Ignoring mirror matchups, the number of potential matchups scales triangularly (muahaha), so that even a single additional race would double the potential number of matchups. As anyone who has tried to balance anything should know, this makes things exponentially more difficult.
Having only a single non-mirrored matchup gets boring pretty quickly, as anyone who played the first few Command & Conquer games found out (and probably why they moved to a 3-race format in later games).
Having 6 match ups makes things overwhelming, as there is twice as much to follow, to prepare for, and to balance. Twice as many interactions usually means half as much balance, which isn't good for anyone.
- Skill Ceiling
Starcraft is great because it is playable and enjoyable, even for new players; but at the same time, you can (literally) play the game for 16 hours a day for years, and still not have mastered it. There is always some new facet to be explored.
Starcraft is the game that spawned the term APM (actions per minute); which measures your ability to command the battlefield. Good players usually have very high APM; 200 is a common threshold for skilled players to reach, while some players will go to 300 and higher.
Top-tier Starcraft players are in a world unto themselves; they have such mastery of the mechanics and strategies of the game that regular players don't stand a chance against them. Watching Pros is a great experience, and can teach you about how to improve your gameplay.
The skill ceiling is great because it gives you something to work towards without relying on the stick-and-carrot methods employed by RPGs. It also allows player to practise and improve without relying on avatar strength.
- Unit Diversity
Within each race, each unit feels truly unique. There is no overlap between units in what tactical role they fulfill. This goes a long way to giving each unit a distinctive feel and play-style on the battlefield.
Starcraft employs a "rock-paper-scissors" approach to its unit design, which ties in very well to scouting. It is vital to the game that you keep tabs on what your opponent is doing, and you prevent him from learning too much about what you are doing in turn. If you see your opponent stockpiling Scissors, you'd best start building some Rocks, or else your Paper will get shredded.
This is better than most games, whose units tend to feel pretty interchangeable (C&C, Age of Empires); which tends to result in a monoculture of the best unit available, with the occasional smattering of support units.
By making various units "super-effective" against others, it forces diversity and interesting unit compositions to the fore-front of battle; also ensuring that the engagements themselves are involved and benefit skilled tacticians more than '1-A'ers, as the rocks seek to avoid the paper and gouge into the scissors of their opponent's army.
Part of what makes Starcraft so great is the community that plays it. Starcraft has a far better community than League of Legends (which is notorious for its troll-infested player base)
In addition to the generally nicer players, there are also dedicated community sites, such as Team Liquid, that provide forums for players to discuss Starcraft, or just life in general. It is also a great place to find player streams; professionals or otherwise who broadcast games.
Starcraft is a game great for both watching and playing. I heartily recommend it to anyone who is looking for an outlet for their creativity and dedication. It is not an easy game, but is fun and rewarding; even if is occasionally frustrating that you are not as good as the Koreans out there. But more on that later.