If your deck is below 30 inches, a railing is not required. With that said, if you choose to build a deck, even if it is only 24 inches off the ground, that is still high enough that even an adult could injure themselves. When you take your kids and pets into account, the risk is even higher.
If you’re planning on building an outdoor deck this year, brace yourself. A national lumber shortage has sent material prices through the roof and made wood difficult, if not impossible, to find in some regions.