Wash and slice the cucumbers into uniform 1/4-inch thick rounds. Place the sliced cucumbers and smashed garlic cloves into a clean, quart-sized glass jar or container.
In a small saucepan, combine the water, vinegar, salt, and sugar. Heat the mixture over medium heat, stirring until the salt and sugar completely dissolve. Do not boil.
Remove the brine mixture from the heat. Stir in the peppercorns and dill. Let the brine cool for about 10 minutes.
Carefully pour the warm brine over the cucumbers and garlic in the jar, making sure the cucumbers are fully submerged. Leave about 1/2 inch of headspace at the top.
Seal the jar tightly with a lid. Let the jar cool to room temperature on the counter for about 1 hour.
Transfer the jar to the refrigerator. Chill for a minimum of 24 hours before eating for best flavor and crispness. Pickles will last up to 3 weeks in the refrigerator.
Notes
For extra crispness, you can add 1/2 teaspoon of pickling lime or grape leaves to the jar before adding the brine.
Adjust the garlic amount to your preference. For a stronger flavor, slice the garlic instead of smashing it.
If you prefer a spicier pickle, add 1/4 teaspoon of red pepper flakes to the brine mixture.