If you have been served with a Statement of Claim you can respond with a Statement of Defence. If you need more time to respond you can use a Notice of Intent to Defend. If you do not want to respond but still want to be notified when things happen in your case you can use a Demand for Notice. If you do not respond at all you can be noted for default and a judgment entered against you.
There are some specific situations where you can ask the court to strike out the Claim. The court can make an order to strike out a Claim that does not show a valid cause for a lawsuit or a Claim that does not comply with the Rules. There are other situations as well. Part 3 of The Queen’s Bench Rules of Court (Rule 3-13) outlines these situations.