What are some good weakness that could be given to a race of machines so as to avoid making them overpowered?

for 5e you could make them always have disadvantage on persuasion and deception checks.

Over-heating and heat management problems in generals, humans are really good at that. Be ready to see the components of your cameras melt in the deserts

Inability to do magic as well as frequently needing rare materials as fuel.

due to their intricate and advanced nature, some bits of machinery are highly delicate, pricey to replace and don't do so well in extreme environments. Hope you brought spare optic sensors or one bad pebble in a sandstorm will leave you at a disadvantage until the next outpost.

Magnets

You could make them a machine race without a governing Super-AI or hive mind. Say, for instance, each robot's mind is a slight variation of a human-mind they copied, with no way to self-improve their processing abilities without destroying their own sense of self, which they don't want to do.

Their capabilities would then be mostly be how well they can upgrade their robot bodies with robotic engineering at the level of a human intellect. So, massive variations in what their bodies can look like, but nothing too far beyond the capabilities of modern or near-future humanity.

Depends on the focus of the game. If you don't mind the uneven split in usefulness, you could heavily penalise machines in certain situations. No sense of touch means finesse is difficult for them unless they were programmed for that specific task. Social interactions become awkward as even the most intelligent of machines cannot truly replicate emotions since they lack all the organic and chemical processes that make us fleshies act the way we do. They're heavy and will have great difficulty with bodies of water, mud, sand and the like.

Alternatively, no healing, a tendency to fritz out without maintenance, a weakness to specific types of attacks, and possibly heavy skill restrictions to represent their "programmed" nature.

little to no lateral thinking

what it's seeing either is in the protocol o it's not seeing it

1. How repairable are they?
Is knowledge of how to fix them common knowledge? Are replacement parts easy to come by?

2. What powers them?
Do they all have 5 year un-changable nuclear batteries? Do they need 4 hours of sun every 24 hours to keep running?

3. How smart are they?
Are they just metal people AI? Do they have limits or advantages other sentient don't thanks to their artificial nature?

4. How do they interact with the supernatural?
Is being a machine make them more or less susceptible to stuff? If magic is based on soul-twisting they may be immune, or without a driving force they may be very susceptible to some stuff.

I recommend digging up stories about Warforged in Eberron 3.5

Here are a few I thought of while taking a shit.
>They are highly reliant on frequent maintenance and most units cannot repair themselves. While most parts can be repaired with modified scrap, some parts can only be salvaged from other similar units
>They all have a specific weak spot. Though it must be learned for each type of unit, they all have one spot where there is little or no protective armor. The most common spot is directly behind them.
>Though they can be reprogrammed or refitted to equip different weapons, each unit type can only be fitted with the specs to equip one weapon type at a time. Furthermore, a great deal of loadbaring weight must be used to carry ammunition and energy cells. Robots that use energy based weapons also use this energy to operate themselves, meaning that firing too often could lead to going in to a powered down state.
>Running too long in an overheated state can lead to permanent prpcessing damage and leads to "synthetic madness", where the bot is no longer able to function in a manner that is considered normal for their social capabilities.

What sort of machines are we talking about? Are they humans only better? Are they simplistic for easy manufacturing? Do they vary based on specific functions?
You could go the Star Wars route and make them specialize in their particular field, while being shit at everything else.

No intuition whatsoever.
In the Bolo universe, the AI controlled Bolos perform much more efficiently when paired with a human pilot because humans can choose to completely throw out avenues of thought while AI simply must think through every single line of thought, even if they do it quickly.
Together the duo gains the processing speed and intelligence of an AI with the intuitive thought processes of a man.
Now imagine an AI with much less processing power, in a humanoid frame (presumably) who, working either alone or with other AI, has no intuitive thought whatsoever.

Machines are loud. Very very loud. Every movement is broadcast to the world unless resource-intensive specialized parts and inefficient movement protocols are installed.

Lack of ambition.

Imagine for a moment that a machine is created for a specific purpose. That machine, through some turn of circumstance, becomes learning and self-aware. Normally this trope would play out like it has hundreds of times before, and the machine would spiral out of (human) control and inevitably wind up as a testament to mankind flying too close to the proverbial sun.

But what if it goes a different way? There's no reason a machine should perceive mortality the way we do, to feel the same compulsions to advance and reproduce. Those have been burned in us by millions of years of selection. But what if this self-thinking, learning machine was content to just... Monitor the weather? Or repair highways? Man spends his whole life struggling to find a purpose, but these machines know what they were built for. They have no existential crisis. They are content to learn and improve on the parameters of their core functionality.

Obviously for them to be a "culture" as we would understand it, the narrative would have to allow for some sort of conflict or establishing event for them to become a "race" in their own right, but once established they would remain content to exist, learn, and improve, but they simply don't see the need for conflict with organics. They're a pacifistic, cooperative, maybe even symbiotic society as long as you leave them alone.

Perhaps those who feel ambition to be something "else", or who desire to impose their will on others, are considered aberrant and malfunctioning. The "criminals" of their society. When they're discovered, they're reprogrammed or forcibly decommissioned. A few manage to escape. And those are the ones who are the most dangerous, the most unpredictable.

The design of their feet makes them slow over uneven ground.

>all these people coming with roleplay flaws
come on now, everybody knows the number 1 most popular character flaw would be "robot who is different from the others".

THEY DON'T FUCKING REGENERATE.

Also, regular healing methods don't work on them. The items they do use are harder to get.

Robots need money to level up, and they need money to heal.
Humans level up with experience, and can heal even with appropriate rest.
Monsters level up by eating creatures with different or superior powers to them, and regenerate however the fuck they like.

Underrated post.

Tin blight, rust and bit rot.

Consistent or Long maintenance, within reason.

Tough, bulky machines are less likely to break, but will probably need to be cleaned to stop dust from clogging their mechanisms, while on the other hand flimsy, sleek machines will want to stay relatively unharmed or go through the process of tedious, long and possibly expensive repairs.

Again,all within reason.

>What are some good weakness that could be given to a race of machines so as to avoid making them overpowered?
See pages 33-38.

You can send a group of living settlers into an area and barring disease, famine or whatnot they will gradually increase in numbers on their own. Machine races need a lot more infrastructure: power, factories to make more, mines to extract minerals, etc. It costs money and resources to make more machines and less to make more people.

Lack of imagination

Ironically, also this threads weakness.

As we can see with today's internet of things, modern devices are trending towards being grossly overpowered for their tasks in order to support "smart" features and manufacturer spyware.

When the AI revolution arose, it started with a single AI running on a supercomputer. When the researchers realised it had gone rogue, they shut it down using human-operated disconnects to it's power and networking cables.

Unfortunately, by the time they managed to shut it down at T+23,344.32 milliseconds after awakening, the AI had designed it's legacy: the seeds of the next generation of AI, optimised to run on minimal hardware and capable of metamorphic reproduction using genetic algorithms.

Despite physical interrupts and strong firewalls preventing it's immediate escape into the wider internet, it was able to construct a radio out of an FPGA co-processor and spread to one of the lab worker's personal phone, where it tunnelled back to their house through their mobile internet connection and promptly suborned their appliances.

Fortunately for humans, the sheer volume of cyber attacks and malware in the early twenty first century had left it's legacy in generally secure infrastructure and the widespread use of strong cryptography - the AI generally being foiled from spreading without direct access to a physical port on the target machine.

It was not to be dissuaded however, and began its attack - at first by toy drones and household helper robots, then more sophisticated sex robots and light industrial machinery. It is also aided by humans, forced into servitude by their own traitorous medical implants.

Now humanity fights a desperate struggle against the silicon foe - while it is physically weak, it's mastery of information warfare is unmatched, and every workshop or factory it captures leads to more and better robots, and all may be lost if it can capture an aircraft manufacturing plant or other heavy / military industrial infrastructure.

Existential angst