A drum rug reduces movement of a drum kit while drumming by providing fiction. A good drum rug would have an anti-slip base to keep it firmly in place while you’re on the drum kit.
If you’ve ever drum on a kit set up on a smooth flooring, you’d notice that your bass drum and hi-hat shifting slightly, especially if you’re in an intense drum solo.
The vibrations created when you drum causes the drum kit to twitch or shift slightly while you play. If you’re in for a long session, you’d inadvertently feel the difference towards the end. Your posture is off, your pedals don’t seem to function as efficiently, etc.
This is also apparent if you’re using electronic drums with a single frame. You may start noticing that your aim is off or feel that your e-drum triggers are off.
Using a drum rug helps to reduce these movement and keep your drum kit in place.
Why do they use drum rugs in recording studios?
An added benefit is that it functions as a shock absorber, reducing the amount of noise sound that’s transmitted to the rest of the room (or your apartment).
You’ll find the recording studios will set up their drums (and even cajons) on drum rugs for this reason – there’ll be less noise being picked up by the mics used for the rest of the instruments.

Should I put a rug under my drum set?
Yes.
Well, if you are struggling with a drum kit that moves while you drum, then definitely.
If you’re just starting out, its better to do it right the first time and get a rug.
If you’re tight on budget, you do not have to get a branded drum rug. You can use a carpet or a mat, but there are a few considerations you need to note. I shared more here.
And if you need help choosing a good drum rug or mat to start with, I shared my pick of the 5 best drum mats or rugs, arranged by budget.