在幻想戰役（例如D＆D）中，如果玩家找到了魔法物品，他們通常必須找出它是什麼，它如何工作，是否被詛咒，等等。
在後世界末日（就我而言是未來派）的戰役中，玩家將如何找出什麼奇怪的槍，例如，他們發現了什麼？我不想簡單地說"您找到一支能使您+2命中率的槍"，但是我不確定玩家可以使用哪些其他方法是最好的。
很明顯，他們可以使用發現的任何武器去找專家，或者對發現的物品進行實驗，或者使用我可以介紹的某種形式的分析（專用計算機，使用某種技能）。
我覺得我可能會缺少一些東西，但這可能僅僅是因為我已經習慣了玩家尋找物品並使用"傳奇知識"，"識別"等等。
您過去使用過什麼？效果如何？我是否錯過了一個非常明顯的解決方案？
P.S。我正在查看的系統特別是無數星號，但我認為這個問題至少部分是系統通用的。
A simple way to do this is to tell the players a little bit automatically, a little bit with a relevant skill check, and all of it with a bit of experimentation.
First, tell the players automatically that this item is special. Something like "This gun is of surprisingly good construction." or "This computer is very well preserved, and might even work!" This lets the players know that they should probably hold onto it, at least until they figure out exactly what it does.
Second, allow some form of skill check to get more information. I don't know the specifics of Stars Without Number, but in a d20 Modern game I would typically use a Knowledge roll that was appropriate to the item in question. For example, "This gun is custom Colt Double Eagle, with a lengthened barrel and custom grip. It probably shoots better than other pistols." or "This computer is an Alienware laptop. If you get it charge up, it'll be pretty powerful."
Whenever the player uses the item, secretly add it's bonus to the check. For the +2 to hit gun, just add 2 to their attack rolls without telling them. Once they've used the device for a while, let them know exactly what it does. For example, "That gun you've been using for a while? It gives you +2 to hit. Refigure your attack bonus to include that." or "The computer that you recovered three days ago gives you a +2 to Computer Use checks."
Of course, this all assumes that you don't want to simply tell your players what the item does outright. I've found that for simple items where the only enhancement is a bonus to a check, it's simpler to just tell the players outright when they get it. For more complex items, you may want to be more reticent, but it's perfectly valid to tell your players what they've found flat out.
Gamma World 7th Edition gives you special items by saying "This is a pile of Tech, you get x draws from the Omega Tech deck". All the info about what it does is on the card, so you can use it immediately. Omega Tech is also fragile, ie, when you use its ability it has a chance to break and become useless.
One thing to note is that in all the settings I can think of (Gamma World, Fallout, Apocalypse World) there are very few "magic" items that give flat bonuses to actions. This helps preserve the flavour that stuff is generally awful and skill carries the day.
Special items should do (not just be) something special and give their user a new option. An IR scanner, so they can see heat signatures through walls for instance. For these items, experimentation and intelligence/science/knowledge checks should help the players determine their function(s).
Science knowledge was potentially lost in any post apocalypse settings. It does not mean that the scientific method was lost. Althought, it might have as in A Canticle for Leibowitz by Walter M. Miller which strangely enough does focus on knowledge preservation amongst other things. But I digress.
Mostly, you will want the players to do a little of evidence based practices and using some of their hard found logic to come up with ideas as to how to determine what the exact "bonus" the item provides. In your case of the +2 gun and assuming a 0-9 skill scale, it would be 20% more accurate in trials compared to a standard gun.
This works for some things but not others. What about that vial of glowing green liquid? Bio hazard or medical nanotech? How do you find out? By having a lab and doing some (careful?) experimentation. This could lead to a whole adventure: find the items, look for a lab and scientists, help them fix a problem they cannot solve but your party can (bandits?), then allow them access so they can experiment.
Do not look at special items as a +X. That's tedious. Look at how those special items do enhance your story. One of the James Bond tropes is that he will use all the gadgets he gets given by Q in the course of the film. They are there to facilitate the story, not be cool items on Bond's character sheet.
Take a look at real life – how could a soldier determine the properties of a random gun they found lying on the ground?
If it's of an unfamiliar construction (i.e., they are unable strip it down, clean and reassemble it) then they wouldn't even know if it's not completely broken until they test-fire it, much less any other properties.
There are standard methods for measuring accuracy – spread of bullets at range X; so after firing a dozen rounds at a controlled range they'd be able to notice 'this gun is really [in]accurate, +/- X to hit'. Do note that in post-apoc settings ammo may be scarce and spending a magazine on just that might be impractical.
Features common to that model (unlike accuracy which could vary between different items of the same model) would be found out by either experimentation or outside info (manuals, pre-apoc datastores).
