After watching some of my replays, I realized that when playing against other Terrans their economies jump significantly larger than mine even though I don't keep unspent resources long (average unspent about 200-300), and I think it's due to the use of Mules. Is this true? Do Mules significantly impact the initial economy size of Terrans? I realize that one Mule can produce about 250 minerals at no impact to supply requirements, and that the rate they pull in minerals is significant.
So, my basic question here is that if I'm not using Mules I really can't hope to compete economically with a Terran who is?
Best Answer
Short answer: No.
Long answer: The reason is fairly simple. You will fall behind in income. If you fall behind in income they will be able to make more units/tech up more than you. This will win your opponent the game in the long run. Think of it this way, if you have more money, you can get more stuff.
Now keep in mind that you might want to keep enough energy for one scan just in case you need detection for a cloaked banshee, but with proper scouting of your opponent you will know if you can spend the energy on a scan or a mule.
You will always want to use MULES to keep your income up, ideally dropping them at your expansions before your main. The reason for this is to extend the time that you can keep mining from your main base which is generally more secure. If you end up mining out your expansion quicker it's not a big deal because it's a more exposed position so you want to gain as much as you can from it in the shortest amount of time.