There are lots of great questions and answers on this site about how and why bipedal mecha are near useless on earth, and why spiderlike mecha could perhaps have some niche uses which are unlikely to justify the costs necessary to develop them. Reasons include square cube law, movement and balance issues, repair issues, and lots of other things which basically boil down to “they are more expensive and far less useful tanks.”

But what if we take planet Earth out of the equation? I’m not necessarily talking about using handwavey “alien technology” to make mecha good, but more about how different resource availability, dominant terrain types, weather patterns, settlement types, and even factors like gravity could influence the effectiveness of mecha in contrast to modern combat vehicles and weapons.

EDIT: To clarify further, I am talking large mecha, Titanfall or Metal Gear size, ideally piloted, but not melee combat mecha with swords and things like that - more like “what changes to physical and planetary conditions would make legged armoured combat vehicles more viable than wheeled or treaded armoured combat vehicles?”

  • $\begingroup$ This might be closed as opinion based, but I'm not certain if it will be. Perhaps consider something like "What's the minimum change to Earth needed to achieve [rest of your question goes here]." Interesting question. Looking forward to answers. $\endgroup$ – Ranger Jun 20 '19 at 17:18
  • $\begingroup$ Do you want regular, house-size mecha, or small, dog-sized mecha would be Ok? $\endgroup$ – Alexander Jun 20 '19 at 17:28
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    $\begingroup$ This is a good example of our Judging when a question is a duplicate discussion. I consider this a fundamental duplicate of this question (and I'm voting as such) because there's nothing you can do to the planet, mecha will never make sense anywhere but in fiction. If you think my vote is unreasonable, go to that Meta link and participate. I believe this is a 1+3=4=2+2 duplicate. $\endgroup$ – JBH Jun 20 '19 at 19:04
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    $\begingroup$ Possible duplicate of Advantages of "Spider Mechs" over Tanks? $\endgroup$ – JBH Jun 20 '19 at 19:04
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    $\begingroup$ Just because that question incidentally answers this one, does not make the questions the same. A person with this question can not reasonably be expected to look up 'Advantages of "Spider Mechs" over Tanks?'. You and I only know to find the answer there because we participated in that discussion ourselves. $\endgroup$ – Nosajimiki Jun 20 '19 at 20:29