In the Rage of Mages magic section of the shop you will notice that some items has the "Turning Speed" magic enchantment.

In cheats code you can reproduce it by typing "#Chicken + enter" (to enable cheats in Rage of Mages 1), or "#Coward + enter (in ROM2), and then #create Uncommon Steel Chain Boots {rotationSpeed=10}" to summon a pair of test boots.

You can put the number you want, in the shop Ive found boots with +3 turning speed, but can't notice any difference, so Ive tried with higher numbers, and still not happening any change in stats, or in the movement.

For what is that stat?

It is for when the character changes position. Literaly only whatit does is speed it up when the character changes direction. Facing north to south, and such nonsense.

The general speed, whatincrises movement speed can be useful to ambush from fog of war, but the turning is pretty pointless.