How can I create cutom effects with properties for Adobe Captivate?

[Pop04]

Is this possible to create a custom effect with properties for adobe Captivate?

[Lilybiri]

Can you explain more in detail what you want exactly? Which version of Captivate are you using? Do you want output to SWF, HTML or both? I'm asking those questions because effects are more limited for HTML5 output.

Do you want to tweak the existing effects or create totally new effects? Long time ago, when effects first appeared, I published this article:

Editing Motion Paths and Reusing Customized Effects - Captivate blog

Each effect is defined by a XML-file, you can tweak that file as well. Flash can be used to create new effects, export them as XML. But as I told, output is very important.