From the Phaser forum:
"Dynamic pathfinding demonstration for a browser-based RTS game I'm working on called "Kings & Kastles:"
"A separate grid / matrix is re-created each time a unit tries to find a new path. However, to save memory, the grid size is only as big as the distance between the units origin and destination. So two things are dynamic: the grid size and the possible walkable / unwalkable nodes which are different each time the grid is recreated."