StarCraft Terran Mission 10
This is by far the most difficult of the Terran missions, so don't despair if you have trouble completing it at first. The following guide should help you achieve victory...
First, get your SCVs to work on gathering minerals. Have your command center queue up more SCVs and put these to resource gathering right away.
Move one group of marines and a siege tank up the ramp to the right, and the other up the ramp to the left. The group on the left may take fire from a siege tank, if so, attack it immediately.
Select one of your first SCVs and have it build a barracks. When the barracks is ready, start cranking out marines. Use the SCV that built the barracks to build a bunker at each edge of the ridge which lies just to the northwest of your base. Man the bunkers with marines.
Continue to produce SCVs at the command center. Put them all to work gathering gas and minerals. Select two of the SCVs for building duty - have one produce more supply depots and the other to continue to build structures until you have built all that are available. Also place missile launchers behind your bunkers and around your base area.
Now that you've established your position, it is time to implement the strategy to win the scenario - contain and expand. You must try to contain the red and white armies to their bases while you expand out to the mineral fields at the center of the map. While implementing this strategy, it is important to keep in mind the tendencies of your enemies. Red prefers to use siege tanks and will send them at you in groups of four or more. To counter, keep plenty of wraiths near your left flank. On the other hand, white likes to use ghosts backed by a combined arms force. Fighting white is trickier, hit his attacking forces with a combination of wraiths and tanks. When his ghosts start locking your units down, perform a sensor sweep to reveal their location and send in marines to take out the ghosts. Try to keep some wraiths in reserve to help support your marines in case your initial force is stuck in lockdown.
Once you have a force of marines and a couple of goliaths ready, attack to the east and clear out the forces situated there. This in not a very strong enemy position, so try to hit it fairly early in the scenario before it is beefed-up with more units.
Next, you need to move quickly to the northwest and build bunkers in front of the bridge which leads to the red base. Man the bunkers with marines and add a few wraiths to monitor the bridge for tanks. Back the bunkers up with missile silos. Red will now be pretty much contained. He will try to hit you periodically for the rest of the game, so have some troops in reserve in case he breaks through your defenses. After you have stopped the incursion, immediately rebuild your defenses at the breach.