Extracted from the 30 Mecha Design Flaws submission. Edited and reconfigured as a setting neutral piece for use in military aspected settings and most if not all flaws can be used on any vehicle or large piece of hardware.
The 228th Mountain Lion battalion faced a situation not entirely unlike General Custer some 500 years before. Like Custer's men, the 228th was almost completely destroyed, despite their laser cannons and drop ships.
All you need to stop a brain is a bullet.
30 generic problems to dole out for homebrew, custom made, and scratch built machines
The walking siege engines of the Cosmic Era
The Rocky Mountain Republic owes in large it's existence to a single limited run of primitive mechs, the Assault/Bombard Mech model 1.
Technology in the Cosmic Era can become corrupted and infested. When this happens to a mecha, the result in codenamed a Hekatonkheire.
The home base of the mighty mech
The reasons that mecha are not reliable as weapons of war are manifold, but the world changed more than many people expected and the way wars are fought have changed greatly since the middle of the Petroleum Era.
A common light mech of the Atlantic Federation
The ultra minimalism mech, for the common consumer
While technically alive, magnagogs have little in the way of personality and are driven via telepathic command.
The Sogans were a mystically aware technological society. Queen Stavarang is the last surviving Sogan in the galaxy
In nature, for instance, a rhino has flies and ticks etc, that live on the hide and live off the blood. Rhino will visit and lie in ponds where turtles will clean the underwater portion of the ticks and a species of bird will clean the the top of ticks and other parasites. What if where the characters camp there were a species of animals that lived off wounds of the creatures. PCs camp. Anybody with wounds on there body are soon covered with small rodent - insect - shadows - whatever. Would immediately see it as a threat I would imagine. But perhaps one of the wounded didn't wake up when it happened, and when they did finally wake they were completely healed. Perhaps somebody was warned of something attacking them but they were able to notice that the wound was actually getting smaller instead of larger. Or maybe they successfully beat the creatures off them and don't notice an improvement, marking this place never to rest at ever again....later learn that villagers send their wounded there but they keep it a guarded secret because they don't want all the attention or traffic and what comes with such a special gift. Could turn into something more too if characters decide to start blabbing about it.