Why is movement in D&D (and many other RPGs) a fixed variable? It seems to me a lot of tension could be added to combat by requiring a die roll after declaring a move. Will I be able to close to melee range with the wizard, or not? Can I go around the square with the caltrops and still beat on the orc this round?
Here's the basic idea: 20 feet of movement gets you a d4 squares of movement, while 30 feet gets you a d6. A little chart of some sort can be extrapolated further from these two data points. A double move would be 2dX but charging would be dX times two.
While I'm re-writing movement systems for games, how about Savage Worlds? Why is walking certain but running risking? (I.e. a normal move is 6" but a run is d6+6".) I say flip those around. Make a walk d6 inches and running adds 6 to that.
I don't have either the SRD or my copy of Savage Worlds in front of me as I write this, I'm just brainstorming here. If you foresee a conflict between the rules as written and my idea, please let me know.