Gaming

I don't know this specific case, but my guess is that damage is a set amount per frame that a collision overlap is happening. This is perfectly valid if it is biased by the delta between frames. It means things get a little wonky at low framerates, but largely work well. But if you are assuming a frame is an exact length, you save a multiplication action, but gain the problem of unlocked frame rates breaking things (and frame dipping possibly causing problems).