System Random Gaussian Float

This node draws a random number from a normal (bell-curve) distribution and hands it back as a FLOAT - set a mean, a spread (std_dev), and how many decimal_places to round to, and it does the rest. The name matters here: "System Random" points at Python's random.SystemRandom, which pulls from the operating system's entropy source rather than the ordinary seeded pseudo-random generator most of ComfyUI relies on. That shows up directly in the schema - there's no seed field anywhere on this node. Every draw is genuinely unrepeatable.

It's one of the "Logic Gates" nodes in aria1th's ComfyUI-LogicUtils, a small pack of logic, random-number, and data-plumbing utilities. Same GitHub account that trained Illustrious XL under the AngelBottomless handle, unrelated project, and one that's been quiet since a last push on 2026-01-21.

Inputs and outputs

• mean - the center of the distribution. Default 0.
• std_dev - spread, i.e. how far values typically wander from the mean. Default 1, and it's clamped to non-negative - a negative spread wouldn't mean anything.
• decimal_places - how many digits to round the result to. Default 2, capped at 10.
• Output - a single FLOAT, drawn fresh from Normal(mean, std_dev) and rounded.

There's nothing to wire in beyond these three widgets - it's a self-contained generator, not something you feed other values into.

Where you'd actually use it

Reach for this specifically when you want unpredictability that can't be locked down - injecting genuine jitter into a batch parameter, adding noise you don't want a user (or your future self) to be able to reproduce on purpose. That's the opposite design goal from this pack's other two random nodes, Triangular Random Float and Uniform Random Choice, both of which take an explicit seed so their output is reproducible. If you need "the same random value every time I use this seed," use one of those instead - this node exists specifically for the case where you don't.

Installing it

ComfyUI Manager → search ComfyUI-LogicUtils → install → restart. Or:

cd ComfyUI/custom_nodes
git clone https://github.com/aria1th/ComfyUI-LogicUtils

No model files, and nothing heavy dependency-wise - random.SystemRandom is Python standard library. A r/StableDiffusion thread recommending lightweight logic packs over WAS Node Suite and Impact Pack pointed at this exact pack specifically because it has no dependencies to fight, and the README's own install hook stays off unless you opt in (COMFYUI_LOGICUTILS_AUTO_INSTALL=1; force it off with COMFYUI_LOGICUTILS_SKIP_INSTALL=1).

Common issues

The one thing that trips people up: there's no way to reproduce a specific output from this node, ever, by design. If you're trying to recreate a batch run or debug why one generation looked different from another and this node was in the loop, that's expected behavior, not a bug - you'll want to swap in Triangular Random Float (which has a matching low/high/mode shape but takes a seed) if reproducibility matters for what you're building.

The other small thing worth knowing: std_dev can't go negative, so if you're trying to "invert" the distribution somehow with a negative spread, that's not a path this node supports. Beyond that, it's a simple generator and the pack hasn't shipped an update since January 2026 - stable, but not actively maintained.