In Settings -> Lead scoring, set a rule and allocate points for the defined condition. In the Scoring Rules, you can Add a new rule or click on the existing rule to edit the rule.

Now to create a new rule, click on the Add button. Create Your Scoring Rules window will then appear.

Select a Condition from the drop down, choose Criteria based on the condition and Enter a Value in the text box.

For the chosen condition you can Add or Less the points. Choose an option between Add and Less, and then enter the points you would like to add or minus for the specific condition (ex: 15 points).

Click on the Apply button to add your Lead Scoring rule.