You can require a learner to complete a previous activity (or multiple previous activities) before they unlock access to an activity by setting a prerequisite rule.
There are two main options:
Learners can see activities that are locked due to prerequisites in the course sidebar (a completion rule)
Activities only appear to learners when the learner has already completed the prerequisites (a visibility rule)
Prerequisite with completion - lock the activity from learners
A completion rule for prerequisites will lock the activity from learners until the prerequisite activity (or activities) are completed.
Learners will still see the activity on the course sidebar, but it will appear locked. Learners will see a message that states All rules must be fulfilled before you can complete this activity.
How to set a completion rule for a prerequisite
To set a completion rule for prerequisites, open the settings menu on your activity page. Select Completion, then choose +Add prerequisite and select the activity (or activities) that you want a learner to be required to complete prior to opening access to this activity.
You can determine if learners can see the descriptive content in your activity with the Activity description visibility setting. To access this setting, click on the gear symbol next to your rule.
The default setting is that Learners can see the activity description if the activity is not open.
If you change the setting to Learners cannot see the activity description if the activity is not open, learners will still see the activity title on the course sidebar, but they will not see the content of the activity.
Prerequisite with visibility - make the activity hidden from learners
You can require a learner to complete a previous activity (or multiple previous activities) before they can see and gain access to an activity by setting a prerequisite rule for visibility. Learners will not see the title for the activity in the course sidebar until the prerequisite activities are completed.
How to set a visibility rule for a prerequisite
To set a visibility rule for prerequisites, open the settings menu on your activity page. Select Visibility, then choose +Add prerequisite and select the activity (or activities) that you want learners to complete prior to opening access to this activity.
Once learners complete all of the prerequisite activities, this activity will appear on the course sidebar. Learners will be able to see and have access to complete the activity.