Conditional Fields

Beyond required fields, the other most common example where you'll want to customize a field's dynamics is to make a field hidden until someone makes a selection in another field.

This comes in handy when you need more info after someone has given you initial info. An example would be when someone selects a car make from a list — Ford, for example — you may want to show them only a list of Ford models to select next. No need to show a full list of all car and truck models that exist. Only show Ford, and only show it if they select it. You encounter this on other websites. 

So you can set a validation that basically says, when Ford is selected in field #1, display field #2 with its list of available options. 

Naturally, the field you're referencing as field #1 has to be a narrow set of options, so the only types of fields that can trigger other fields' validation are radio button and dropdown fields. 

Here's how to set that up.

1. First, create both of the fields involved in the conditional logic. 
2. Click the button to edit the second field — the one that would only be displayed if the first field's condition is met.
3. Choose the field from the dropdown list that would be field #1 in the conditional logic.
4. Choose the selection of the ones you made available in field #1 that would trigger field #2 being displayed.