One-step, one-spell distance

The one-step, one-spell distance is a key concept in sword arts.

Background
The "one-step, one-spell distance" is a radius around a mage, approximately two to three paces, within which no mage can cast a conventional spell faster than an opponent can strike with a weapon. This concept coalesced after High Sorcerer Wilf Badderwell was killed in a fair duel by a nonmagical swordsman in 1132.