I'll try to explain, but that's my first answer at language-section of stack, so be free to ask me

Местный падеж is similar to Предложный падеж in russian so word will answer to question Where?, but main difference that Местный падеж give us information about item's position. Anyway, this difference is so small, that there're no Местный падеж in russian, that's just a type of Предложный падеж. For example:

- Where's Your largest birthmark placed? 
- On my side

In russian

- Где твоя самая большая родинка?
- На **боку**

1. Местный падеж specifies the place of action. So there're usual words like в лесу, в городе, etc
2. There are two preposition used with Местный падеж: в и на (в лесу, на дереве)
3. Местный падеж is Предложный падеж with specifying place of action
4. Use Местный падеж if word answer to Where? and specifying place of action. Anyway You'll use rules from Предложный падеж, 'cause Местный падеж is part of it.

Bonus:

I have no ideas in fact

I'll try to explain, but this is my first answer in the language section of the stack, so feel free to ask me.

The Russian locative case is similar to the prepositional case, so word thus declined answers the question where?. But the main difference is that the locative give us information about the noun's position. At any rate, this difference is so small, that there's no separate locative case in Russian — it simply tends to fall under and be use alongside the prepositional case.
For example:

- Where's Your largest birthmark located? 
- On my side.

In Russian:

- Где твоя самая большая родинка?
- На **боку**.

1. The locative case specifies the place of an action, so we commonly encounter phrases such as в лесу, в городе, etc.
2. There are two preposition used with the locative case: в и на (в лесу, на дереве).
3. The locative is the prepositional that specifies the place where an action takes place.
4. Use the locative if the noun is meant to answer the question Where? and specifies the place of action. Anyway, you'll use rules pertaining to the prepositional case because the locative is a part of it.

Bonus:

I have no idea

I'll try to explain, but that's my first answer at language-section of stack, so be free to ask me

Местный падеж is similar to Предложный падеж in russian so word will answer to question Where?, but main difference that Местный падеж give us information about item's position. Anyway, this difference is so small, that there're no Местный падеж in russian, that's just a type of Предложный падеж. For example:

- Where's Your largest birthmark placed? 
- On my side

In russian

- Где твоя самая большая родинка?
- На **боку**

I'll try to explain, but that's my first answer at language-section of stack, so be free to ask me

Местный падеж is similar to Предложный падеж in russian so word will answer to question Where?, but main difference that Местный падеж give us information about item's position. Anyway, this difference is so small, that there're no Местный падеж in russian, that's just a type of Предложный падеж. For example:

- Where's Your largest birthmark placed? 
- On my side

In russian

- Где твоя самая большая родинка?
- На **боку**

1. Местный падеж specifies the place of action. So there're usual words like в лесу, в городе, etc
2. There are two preposition used with Местный падеж: в и на (в лесу, на дереве)
3. Местный падеж is Предложный падеж with specifying place of action
4. Use Местный падеж if word answer to Where? and specifying place of action. Anyway You'll use rules from Предложный падеж, 'cause Местный падеж is part of it.

Bonus:

I have no ideas in fact