MarkB
Legend
The effect would be to reduce combat to an entirely static affair for anyone without Tumble. No 5-foot step means no co-operative flanking tactics, no stepping out to let another character in to attack, no stepping back to spellcast or fire a ranged weapon, no adjustment to attack an opponent wielding a reach weapon.phindar said:Well, technically it means you can't move 5' and full attack without drawing a AoO; you can still take the Withdraw Action for a double move the draws no AoO from the threatened hex you are leaving (though opening you up to others down the line). There's also the Tumble check, for the dexy-skilled types.
Now, to be honest, I haven't really put the idea through the proper paces; running the likely scenarios through my head and then trying some stuff out at the table. But I think that the main effect of taking out the 5' Step would be that every couple of combat rounds someone would say, "You can't move 5' and Full Attack."
In short, tactical combat would be greatly reduced, creatures with reach would rule the battlefield even more so than with your variable-step rule, and opponents would just stand toe-to-toe, unmoving, until one or the other won.
It'd be boring.