Mechanics
Build Queues
A worker can now queue buildings consecutively. When one building is finished being constructed, if there is another building in the queue line it will go right ahead and begin constructing that building. With this mechanic you can have 1 worker build a string of buildings by adding each one to their queue.
Destructible Doodads
A new game mechanic in Starcraft 2 are destructible doodads. These doodads can be rock formations, statues, trees or other objects to block a units path. These doodads usually block a ramp to a mineral expansion, or a path behind to an enemy base. These doodads have high hit points and defense but can be destroyed by any unit.
High Yield Minerals
There is a new type of mineral this time around, a yellow high yield mineral. This mineral gives an extra bonus of minerals for every batch a worker gathers. This high yield mineral patches are rare and sparse. If one does find a high yield mineral patch, they will need to defend it greatly from enemy units.
Xel'Naga Observatory
The Xel'Naga play a bigger part in the storyline and with that you can find many neutral Xel'Naga structures scattered around the map. One of these structures is the Observatory. When a unit stands next to the Observatory, it activates and reveals an area and dissipates fog around the Observatory.
Auto-Mine
This feature allows you to set your main structures (Command Center, Hatchery, Nexus) rally point to a mineral node or vespene geyser. By doing this it allows a worker to automatically start mining once it has been created. This automates the mining process tenfold.
Line of Sight
Units firing from a higher ground will not be revealed to the enemy player and the units getting hit will not be able to strike back unless they have something to provide them with line of sight of the units above them. This feature greatly supports stationary weaponry like the Siege Tank.
Multiple Building Selection
Multiple Building Selection or MBS is a feature that allows you to select more then 1 building at a time and order a command. This will allow you to build multiple units in succession. For example if you select 5 Barracks, you can hit "M" 5 times consecutively to build 5 marines.
Smart Casting
If you have two or more units of the same type selected and you order them to cast a spell, only one of the units will cast the spell instead of all. That means you wont have many units waste an ability, instead you can tab between each one and cast each one individually.
