Frequent players develop "innate motor motion," allowing them to use abilities without ever looking away from the battlefield.
Numbering hotbar slots (typically 1–9 or 1–0) creates a direct map between the UI and the physical keyboard. This allows players to activate items or skills instantly by pressing the corresponding key, rather than fumbling with a mouse or scrolling.
Allowing players to drag-and-drop items from their main inventory into specific slots is the gold standard for user-friendly design.
