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Right now, if variable A depends on variable B, YOU have to remember to update A every time B changes. Forget once? Bug. Forget twice? "It works on my machine." Forget three times? You're rewriting the whole system at 2am.
Live variables fix this with one keyword: ✨ live ✨ You tell X to follow Y, and it just... does. Change Y anywhere in your code, and X updates itself — you never touch it again. And if you ever want X to stop tracking? A regular set X = ... opts you out.
Let me introduce you to Bobby. Bobby is a player in your map. Bobby has Health. Bobby has MaxHealth. Bobby also has a UI that shows his health bar. Bobby's health bar is wrong 40% of the time because you forgot to call UpdateUI() somewhere. Bobby deserves better.
Here's Bobby's health system WITHOUT live variables (see image) You have to call ALL of these functions. Every. Single. Time. Anywhere health changes. Miss one? Bobby's health bar says 100 while Bobby is literally dead.
Now here's Bobby's health system WITH live variables (see image) Way less overhead. You change Health from anywhere in the codebase and every single value stays in sync. Bobby is happy, Bobby is alive (sometimes).
It gets crazier. You can use a function AS a variable's type. Every assignment passes through it AND it reacts to dependency changes. Bobby just picked up a damage buff. His damage auto-recalculated. Zero extra code.
Want to clamp Bobby's health so it never goes below 0 or above max? Input-output variables let you keep the raw value AND the clamped value. Bobby writes 999, the system stores 999 but displays 100. Lower the cap to 60? It auto-reclamps on its own. Nice try, Bobby.
Live variables unlock three reactive constructs: 🧘 await: pause until something is true 👂 upon: fire ONCE when condition is met 👀 when: fire EVERY TIME condition is met Think of them as "wait for this," "do this once when," and "always do this when." No events, just intent.
"But what if I update 5 variables at once and don't want 5 separate reactions?" Wrap them in a batch block. All the changes happen immediately, but every notification gets held until the batch finishes, so observers only ever see the final, consistent state. Bobby's health bar
Live variables aren't released yet, but they're coming. When they drop, you'll be able to: ❌ Eliminate manual state syncing 🔨 Build reactive UI with zero callbacks ⌨️ Write game logic that reads like intent, not plumbing Bobby can finally rest. Until then, study the docs.
I break down Verse and UEFN features like this every week! From language deep dives to things you can actually use in your maps. If this thread saved you from mass-updating variables at 2am, you know what to do. Follow
@vukefnso you don't miss the next one. Got questions
The "Live" variables are very much like what
@sveltejsdoes for the Web (or in my case Electron Front End). If you ever played with Filtering in my Asset Manager Studio, you can see "Live" variables at work. 😉
