Can you make an offer on a house that is under offer?

The 72-hour clause allows you to make an offer on a house that is under offer.

The 72-hour clause stipulates that the seller can continue marketing a house, and accept a rival offer, provided they give the original buyer 72 hours to fulfill the terms of the Offer to Purchase.

If the buyer fails to do so within 72 hours then the new offer can be accepted.

The new offer should have fewer, or preferably no suspensive clauses that need to be filled.