No Mana Cost Prediction

Your mana, shown honestly

WoW Forever runs on the modern client, which brought along a retail feature: mana cost prediction. The instant you start casting, your mana bar drops by the spell's cost, before the spell has done anything.

It's only cosmetic, since the server still charges you on cast completion like it always has. But it makes your mana bar lie. Cancel a Frostbolt to dodge a pat, get kicked mid-heal, or stop casting to move, and for the whole cast your bar showed mana you never actually spent.

No Mana Cost Prediction turns that off. Your mana bar drops when the mana is actually gone, and not before.

What it does

• The player mana bar no longer drops at cast start
• Mana drops only when the server spends it, the classic behaviour
• Cancelled and interrupted casts never look like they cost anything
• Works out of the box, with nothing to configure

What it doesn't do

It doesn't change game mechanics, cast times, mana costs or anything server-side. It can't: addons only control what's drawn on your screen. It also only affects Blizzard's default player frame. If you use a unit frame replacement, that addon draws its own mana bar.

How it works

Blizzard's player frame listens for a "cast started" event and uses it to look up the spell's cost and subtract it from the bar. This addon stops the player frame from receiving that one event. It doesn't edit Blizzard's bar or values in any way, so there's no taint and no Lua errors from the client's protected ("secret") mana values.

Commands

/nomanapredict works for all of these too. Your choice is saved account-wide.

Feedback

Found a bug, or seeing the bar drop early on a spell or class it shouldn't? Leave a comment with the spell name and your class.