Players are now given instant access to abilities they don't want to use all the time, but may need depending on the situation. This is a massive change to how skills get used in D2. Quick Cast allows you to press a hotkey associated with an ability, and you will automatically cast that spell without changing the keys assigned to your left and right mouse controls. Using Quick Cast and Active Skill Bindings Check the last two options that now appear in this box: Quick Cast Skills and Display Active Skill Bindings. In game, click Escape to select Options, then the Gameplay tag. Right now, these options are not selected by default, so you will need to check these boxes to make them active. Turning On Quick Cast and Active Skill Bindings While you still have your primary attacks and abilities assigned to your left and right mouse buttons, you have ready visual access to all other mapped skills. With Quick Cast Skills and Display Active Skill Bindings, your days of having to remember the assigned hotkeys and scroll through them are over. This was more of a problem for classes such as Paladins who have huge numbers of skills they may use situationally, or for characters who play a lot of alts and needed to remember which hotkeys were assigned to which character and for which skills. This could be awkward in cases where you need to flip between several different skills, and you also need to remember what skills are mapped to which hotkeys, often in the heat of battle. You could change the assigned mouse button skills through mapped hotkeys or by using the mouse wheel to scroll up or down through accessible skills. Prior to 2.3 (really, for the past 21+ years of Diablo II's existence), players were limited to just two readily available skills through the player's mouse - one accessible by left-clicking and one accessible by right-clicking. This also includes the option to display Active Skill Bindings, which displays up to 16 skills mapped to hotkeys on the player's main UI bar. Quick Cast allows players to use abilities with hotkeys without having to select the skill in the UI. The release of Patch 2.3 brought many welcome quality of life changes to Diablo II: Resurrected, but the change with the biggest impact is undoubtedly the addition of Quick Cast.

Diablo 2: resurrected changes