The time it takes for fudge to set can vary depending on the specific recipe, ingredients used, and environmental factors like temperature and humidity. However, on average, fudge usually takes anywhere from 1 to 3 hours to set at room temperature. To determine if your fudge is properly set, you can gently touch the surface with a clean finger. If it has cooled and set, it should feel firm to the touch and not leave any residue on your finger. Keep in mind that fudge can continue to firm up even after it's been removed from the pan and cut into pieces. If you're in a rush, you can place the fudge in the refrigerator to speed up the setting process, but be cautious not to leave it in there for too long, as it can become overly firm or even develop a sugary "bloom" on the surface due to temperature fluctuations.