Is there an easy way to add the same group of sub-tasks to a number of User Stories or even just one

[Warren Minto]

We have a User Story template which has a number (9) of sub-tasks but the team has created the User Stories individually, not cloning the template. I would like to add the (9) sub-tasks to the User Stories they have created without doing it one sub-task at a time. Thanks, Warren.

[Constance Hua]

I see no way to do it without a plugin...

You can use Scriptrunner for this and write a scripts which clones these specific sub-tasks to all issues in jql result.

Or you can search for another plugin which can bulk clone 

[Tarun Sapra]

To create bulk of sub-tasks from UI quickly I generally use (and it's free)!

https://marketplace.atlassian.com/apps/1210972/quick-subtasks-for-jira?hosting=server&tab=overview

If you want to create the sub-tasks every-time an story is created then you can also use the post-functions provided by Script Runner plugin.

[Tarun Sapra]

Without an plugin it's not possible to achieve what you want.