Terran Marauders are cheap and easy to create. You can make 6 or units immediately with just one barracks and one supply depot. Marauders costs 100 minerals and 20 vespene gas which in the starcraft world is considered to be very cheap and power.
Over the years gamers develop the 3 barracks Marauder rush strategy. In this strategy, they do the rush attack for the purpose of gaining the upper hand immediately because if they do not attack as soon as possible, enemy units will go stronger and will have the possibility to win. Since there are many experienced gamers, they come up with this list in order for a player to effectively get the 3 barracks Marauder rush strategy:
1. Create 3 SCV’s and gather minerals.
2. Continue creating SCV’s until you can build a Refinery.
3. Place 3 gatherers to your refinery and build a Barracks.
4. Continue to create SCV’s until one barracks is done.
5. When the first Barracks is done create a Marauder.
6. Build another Barracks and create another soldier.
7. Construct a Supply depot so that you can continue to create another set of soldiers.
8. Continue creating units and once the 2nd barracks is done build another one and continue to create units.
9. Create another Supply depot and when you have created 12 M units, begin to attack the enemy.
10. Be careful when you attack because some gamers close their ramp so that their base won’t be vulnerable.
In the first set of units that you will use to attack an enemy’s base, be sure that their armours are upgraded at least once so that their units will be stronger and harder to kill. If you fail to upgrade them, expect 90% of your troops will die before they could inflict serious damage to your opponents.