If you want to offer a discount only if a booking is made for a specific number of participants, for example only 4 participants, or "book for 4 people, pay for 3 people":
1. Go to Marketing>Promotions
2. Click on your Promotion or set up your Single code promotion or Multiple coupon code promotion (Groupon, LivingSocial).
3. In the Number of participants section, select the minimum number of participants for which the promotion is valid.
For example, if your promotion is valid for up to 4 participants (that is for 1, 2, 3, or 4 participants) select “1” in the Min field and “4” in the Max field
If your promotion is only valid for 4 participants, select “4” in the Min field and “4” in the Max field.
4. Save