Esm is one of those parts of War Thunder that the game introduces once and never revisits.

Short answer

It is worth understanding once properly, because a lot of other things in War Thunder refer back to it.

  • Read the in-game description once, then ignore it.
  • Ask what it is for before asking how to get it.
  • Give a method one honest attempt before deciding it does not work.

War Thunder models more of the vehicle than it tells you about, and the grind punishes guessing. The game introduces it quickly and assumes you picked it up, which is where the confusion starts. If you only remember one thing about it, remember where it appears.

What it is often confused with

Do the cheap check before the expensive one — that ordering alone saves most of the frustration. Whether it is worth going out of your way for depends entirely on how you are playing. Community shorthand around it has drifted far enough from the original meaning to cause arguments. Most of the disagreement you will find online is two people describing different builds.

It appears in supplementary material in more detail than it does in the game itself. The in-game description is technically accurate and practically useless. The community wisdom on this is roughly half right, and the half that is wrong costs the most time.

Whether it is worth going out of your way for

Knowing this does not make you better at War Thunder, but it does make the rest of it legible. Two similarly named things exist, and mixing them up explains a lot of contradictory advice. Screenshots age faster than text, which is why this describes rather than shows.

  • Note where it first appears, so you can go back if you need to.
  • Do not confuse it with the similarly named thing — that mix-up drives most bad advice.
  • Region and platform change more than people expect, so confirm both.
  • It rewards attention rather than preparation.
  • Check which version of War Thunder any discussion of it is describing.

What it is

It is the kind of thing veterans forget they ever had to learn. The name is descriptive if you already know what it does, and opaque if you do not. Where two approaches both work, the one with fewer moving parts is the one to keep. Most guides mention it in passing and none of them stop to define it.

Early impressions of it are usually wrong in the same specific way. If a step reads as obvious, do it anyway — the obvious ones are the ones people skip and then wonder about. It rewards understanding rather than grinding, which is unusual for War Thunder.

Why people keep asking about it

Its practical value is narrow and real, rather than broad and theoretical. The short version is near the top on purpose; the reasoning is there if you want to know why. Its role has changed across updates, so older discussion describes something slightly different.

The wiki entry is thorough and buries the actually useful part six paragraphs down. Where something depends on your platform or region, that is called out rather than glossed over. It shows up in more places than its introduction suggests, once you know to look.

Where you encounter it

It became noticeably more relevant after a change the patch notes barely mentioned. The developers have changed their mind about this at least once, which explains the older advice. It is more consequential in the late game than the early one, which is why first impressions mislead.

Where people go wrong

  • Skipping the prerequisite because it looked optional in someone else's summary.
  • Rushing the last step, which is usually the one with the actual requirement in it.
  • Grinding a method that was patched months ago because a thread still ranks well.
  • Ignoring the platform-specific note and then wondering why the steps do not line up.

War Thunder FAQ

Does this work the same on console and PC?

The logic is identical. Menu paths and button prompts differ, and any real difference is flagged above.

Do I need any mods or third-party tools for this?

No. Everything described here works with the base game on any supported platform.

Has it changed recently?

Its role has shifted across updates more than once. Anything you read without a version attached may describe an older form of it.

Where can I read more?

The official material covers it in more depth than the game does, and considerably more reliably than aggregated fan pages.

If you only take one thing from this: the answer near the top is the part that matters, the rest is context.