Initializing class variables blueprint


So I have 2 blueprints

1 called spell, with lot of floats such as damage, cost, range…etc

another one. called my character, who needs to have a spell and depending on the spell it will have some different properties.

so what I’m doing is creating a “Spell_C” variable inside the mycharacter. and then I try to set the damage

what happen is that I get the error that says "Accessed none ‘spellQ’ from node Set Damage in blueprint MyCharacter.

I already read about it, and I know is because I don’t have my variable initialized. that’s pretty obvious, but I just don’t know how to initialize my variable so I can use it.

Anybody can help me with this?
thanks very much.

Yeah. I already said it. It’s not initialized for sure. and if I use isValid it always go to false.

Thing is, how can I Initialize SpellQ?

Spell Q is probably not initialised, try using an isValid check to make sure there’s something there.

Same way as any other variable, you set it. If this Spell Q thing is a pointer to an instance you need to spawn the instance first, then assign it to your variable.

Is your SpellQ_C a c++ class? and is it exposed to blueprints?
I think its best to do everything in either c++ or blueprints, and try to avoid making a class that needs both, that said there are definitly times when you need to expose a c++ function for access in BP, but for character stuff like what your doing, your probably better off creating the SpellQ class in BP instead.


and how can I spawn the instance first? could you show it to me? I’m just starting with this blueprint stuff and I’m a bit lost.

Thanks for your quick answer!

Both. SpellQ and MyCharacter are Blueprints. I didn’t touch any code yet tho I started using C++ 3 person code template.

SpellQ_C is the type I created the variable in MyCharacter, because is the only one that allows me to access to the functions and variables my Spell Blueprint has.

Hello Grendert,

Are you familiar with casting? It allows your blueprints to “talk” to each other. Here is a video example:

(You will want to look at the video called “GETTING CLASS BLUEPRINTS TO TALK”)

I hope this works for you.


Try Spawn Actor, and put the result into your SpellQ variable before its used.


thanks all for the quick response!

Actually the tutorial helped me to understand a few things that I didn’t have understand properly. so thank you very much for that!!

Althought that didn’t solve my problem because I wanted to do that with the blueprint script itself.

Try Spawn Actor, and put the result
into your SpellQ variable before its

That actually was the solution I was trying to find!

In case anyone find the same problem. that’s how I solved it