Pathing

From SC2Pod

Pathing, or Pathfinding generally refers to the plotting, by a computer application, of the best route between two points. We need not go into detail here, but suffice to say that pathfinding in the sense talked about here is the way in which a moving entity (such as a Marine) finds a path around an obstacle.

In Starcraft 2 the pathing has been improved drastically from the original StarCraft. Algorithmically, the number of paths has increased many times over, giving units many other options to travel other than going in a straight line. This allows for more of a group movement dynamic rather than a column movement dynamic. This has been further evidenced in many of the new Starcraft 2 videos, as we notice that units now move in a wide patch rather than one behind another. Units also move together in groups, rather than waiting for the first in line to start going, therefore eliminating the "traffic jam effect" seen in many Starcraft games.

Collision seems to also have been improved a bit, as units now bounce slightly when hitting each other at high speed rather than get stuck on each other like in original Starcraft. This gives a more fluid feel to the movement as units no longer lag while deciding which way to go.

When SCVs, Probes, and Drones are collecting minerals, they behave similar to SC/BW units in the sense that they don't collide with each other. However, in a new addition to SC2, regular units no longer collide with them as well during mineral extraction.

Furthermore, units will react much faster when stuck. In the original Starcraft, when a unit is stuck, it had to decide on either backing off and going the long way round or just standing there befuddled. In Starcraft 2 units will retry to get in by any small opening that can be found.