But, when we edit the page layout, there is no option to remove Probability from page layout. Hide mouse over the field in edit page layout, you will not see minus icon next to it.
The same for the following fields in Opportunity, you cannot hide them from the page layout:
- Opportunity Name
- Account Name
- Close Date
- Probability (%)
When you edit page layout, there is a blue dot before the field name. You cannot hide all fields with a blue dot in page layout.
You can hide the Probability (%) field from Field-Level Security:
- Setup | Customize | Opportunity
- Look for Probability (%) and click the field name
- Click 'Set Field-Level Security' button
- Untick Visibility checkbox for profile do not want to see this field
- Save and done
Since we are hiding the field in the field-level, the user will not able to see it anywhere, including in report, or in the scenario, you have many record types and page layout, the user will not able to see it in the other page layouts as well.