Another thing which influences gameplay is the ability of the players to travel through the game world. From level 1-9/10 the players are completely dependent on the DM for the possibilities of large scale travelling, while from level 9/10-13/14 they can fast travel anywhere in the world, and from level 13/14 they can travel to any plane.
Travel
1-9/10: Regional travel: Walk, ride, sail, tactical fly...
9/10-13/14: World travel: Overland flight, teleport, ...
13/14-20: Planar travel: Plane shift, gate, ...
Travel
1-9/10: Regional travel: Walk, ride, sail, tactical fly...
9/10-13/14: World travel: Overland flight, teleport, ...
13/14-20: Planar travel: Plane shift, gate, ...