How to make my index consider the cover

The index is correctly counting the pages, but I found no way to make my index consider my work for printing, with a cover in my case, this mean the title page is actually the 3rd page of the book, then comes the credits page (4) and index page (5) I added a blanc page (6) to thave my first text on the right (7) the index however is counting this first chapter as page 5 and of course it is the 5th page of my document, but I need to add +2 offset to the page count, both in the page numbers and in the index.

Your description is unclear. From what I understand.
First page is what? Outside cover?
Second page is what? Inside cover?
Third page is title.
Fourth page is credits.
Fifth page is index.
Sixth page is blank.
Seventh page is where the text starts.

On what page do you want the page count to start? Place the cursor before the first text of the page you want to be page 1. Right click and select Paragraph>Paragraph… Go to the Text Flow tab. In the Breaks area on the right side, select Insert. Leave Type as Page. Leave Position as Before. For With page style, select the appropriate page style. For Page number, select 1 (this should be a right hand page for a bound book).

I get the impression you are trying to use one page style for all of the pages. You should always use a minimum of three page styles including First Page, Left Page, and Right Page for a bound book.

What do you call “the index”? Table of contents or alphabetical index?

Page number parity should not be handled with manual page addition because edits can change yur document layout, forcing you to change your manual additions. There are better tools like page styles which can be constrained to left or right, an text flow properties.

Never use the offset parameter for this purpose. Offset does not change the page number. It requests to look for a different page with the consequence that if the page does not exist, the returned number is “blank” (you no number).

Mention your OS name, LO version and save format. If you save .docx, all suggested recipes won’t work because M$ format has no notion of page styles.

I’m printing this as PDF, working on W10 with the latest version. I really wanted to use I, II, III numerals for the first paged excluding the title, and 5, 6, 7 and so on for content pages. But using page styles is messing up my book for some reason.

I really wanted to use I, II, III numerals for the first paged excluding the title, and 5, 6, 7 and so on for content pages. right now I have a title page, copyrights, index, about, foreword, introduction then the content chapters starts. To all of this I’ll need to add a book cover. if title page start at 1 but it is not shown then my first content should be on page 5 if I counted it right.

This is no usable information because release upgrade proceeds at different pace on the various platforms. Mention version with its 4 components.

Then your are not familiar with styles (not only page styles).
Page styles operate on a sequence of pages delimited by “boundaries”. These boundaries are special variant of page breaks (not counting start and end of file). You create the boundaries either manually with Insert>More Breaks>Manual Break where you can chose which page style follows the break and optionally restart the page number (without using an “offset”), or implicitly as a consequence of Text Flow property in a paragraph style.

The page style must exist before you insert the break or change text flow properties. When creating your page style, you choose the type of numbering (Roman, usual numeric, alphabetical, …).

Did you see my suggested solution below with step by step directions? It may not match what you actually want since that seems to be changing. But you should learn enough working through the steps in a new document to figure out how to set up your actual document the way you wish.

I think is the bit of information I needed! In fact I was in a loop with Right/Left page style I could not break (see my latest comment on TXDon answer) So I should create a pag estyle for every page after the Title page, then after the index Page start with Left/Right page styles rotation?

No, not for “every page”. You create (or use built-in styles) for every sequence which has different specification (margins, header, footer mainly). You can reuse a page style if the sequence has the same property as a previous one.

Example: chapters
In your chapters you alternate between /Left Page* and Right Page. A chapter starts with a heading. This heading is usually styled Heading 1 (though identified to Writer as part of the outline at level 1 and collectable automatically into a TOC (= table of contents; this is probably what you call the “index”). You can customise Heading 1 Text Flow tab to require that a special page break is always inserted before this paragraph (thus you no longer need to manually insert the special page break) with switch to Right Page page style. This stops the current sequence (any, even previous chapter alternation Left Page/Right Page) and starts a new one on a right page. If previous sequence/chapter ended on a right page, a completely blank page is inserted so that the new chapter starts on right side.

This also eliminates the need to manually insert your fully blank page. And you don’t need to review the document when you modify it to cope with eventual removal of this blank page when a chapter is expanded. Everything is now automatic.

OK. I think I understand what you want. The following is not the way I would set up a book. But using your criteria and not creating new page styles, try the following. I’m assuming you know how to use the Sidebar.

You will be using four page styles. Go to the Page Styles area of the Styles deck of the Sidebar. The outside and inside of the cover, we’ll use the Default Page Style. You don’t need to do anything to that style. The next four pages will use the First Page Page Style. Right click on First Page and select Modify. Go to the Organizer tab. Make sure Next style is set to First Page. Go to the Page tab. Make sure Page layout is set to Right and Left. Set Page numbers to I,II,III. Click OK. Right click on Right Page and select Modify. Go to the Organizer tab. Make sure Next style is set to Left Page. Go to the Page tab. Make sure Page layout is set to Only right. Set Page numbers to 1,2,3. Click OK. Right click on Left Page and select Modify. Go to the Organizer tab. Make sure Next style is set to Right Page. Go to the Page tab. Set Page layout to Only left. Set Page numbers to 1,2,3. Click OK. The page styles are not set up.

Go to your document. Make sure Page 1 (the front cover is set to Default Page Style). Type “Cover” for now. You can go to Insert>Page Number for each of the pages to check what page this would display. Go to Insert in the Menu Bar and select Page Break. Type “Inside Cover” for now. Go to Insert>More Breaks>Manual Break. In the dialog, select Page Break. For Page Style, select First Page. Check the box for Change page number. Set this to 1. Click OK. Type “Title Page for now. Go to Insert>Page Break. Type “Credits Page” for now. Go to Insert>Page Break. Type “Index Page” for now. Go to Insert>Page Break. Type “Blank Page” for now. Go to Insert>More Breaks>Manual Break. In the dialog, select Page Break. For Page Style, select Right Page. Don’t do anything with Change page number if you really want this to be Page 5 rather than Page 1. Click OK. Type “Text” for now. Go to Insert>Page Number to check the page number. It should say 5. Just continue typing. As the text flows from page to page, the page style will automatically switch from Right Page to Left Page to Right Page. The numbers should automatically go from 5 to 6 to 7 and so forth.

If you need to stop text in the middle of a page and go to the next page, just go to Insert>Page Break.

I eventually created a page style, I had some problems interrupting the sequence of a page style, for example Right/Left page styles alternate each other and I had trouble interrupting this. I needed to interrupt this sequence because I wanted to have the 4th page with no page number, totally blank.

So now I have the following situation: Title Page in page 1 (no page number) here I’m not sure if I need to consider the binding left margin or not. Then I have Copyright Page on page 2 noted in roman II and Index Page on page III, the Fourth Page is empty so that the content will start on the fifth page, numbered as Page 1. From this point on the numeration is all arabic.

I read a few articles suggesting this approach, not sure if this is valid in general or only in some kind of texts. My guess is I should alternate Left/Right Page styles in the content pages, but I was unable to interrupt the numeration so I created a Fourth Page style, perhaps I should have created instead a Copyright and Index pages style? Should I consider binding margin on those pages as well?

It sounds as though you are making good progress elnath78.

If the document is going to be bound with text on both sides of the page, every page except blank pages should consider the area taken up by the binding. While applications such as LibreOffice Writer offer a feature for the gutter, I find it best to simply adjust the margins. By giving a right-hand page a larger left margin and a left-hand page a greater right margin, the visible portion of the page appears balanced with equal margins. This is true even with title pages and pages with front matter.

A title page is generally the first right-hand page across from the inside cover. Following that, the left-hand page may be blank and the right-hand page may serve as a dedication page or a copyright page. Following the copyright page is the table of contents on a right-hand page. This may be followed by a blank page on the left and a preface starting on right. Front matter often uses page numbers in lower case Roman numerals (i, ii, iii). Pages such as the title page, copyright page, and table of contents often are not counted. In that case, the front matter page count would start with the first page of print after the table of contents, usually a right-hand page. The first right-hand page of front matter may or may not have a visible page number. The first page of actual book content is normally counted as page 1. The first page of a chapter (on a right-hand page) often does not display the page number. If a chapter ends on a right-hand page, the next chapter normally begins on a right-hand page with a blank left-hand page beside it.

Besides regular Left-hand and Right-hand page styles, I would have a Chapter page style with a larger left margin and a greater top margin above the chapter name. If the Chapter page has no footer, you might be able to use this same page style for your table of contents page if you want the table of contents to have the same large top margin. You may need left-hand and right-hand page styles for your front matter if you have text on both left and right pages.

If a chapter ends on a right-hand page, use Insert>More Breaks> Manual break. Select the Chapter page style for the Page style after checking Page Break in the dialog. LibreOffice Writer will automatically insert a blank page to the left. The blank page will be counted in the page count, but the page number will not appear on the page. This is what you want.

Given all that I’ve just said, there are books that use other formats.

Wow! that’s a lot of white pages, I always thought people would be pissed seeing wasted space, because more pages means more printing costs. Looking at the books I have here, they really doen’t care of extra white pages, and some are also printed on a yellow-ish paper not perfectly blank and it is still readable.

Printing costs have certainly influenced page layout at times. One chapter might follow another on the same page, every page with narrow margins. Other publishers used white space as a tool to give emphasis to different parts of a publication. Colored printing also added greatly to cost requiring the same pages to be printed several times using different colored ink. Of course, if the inks didn’t line up correctly with one another, the sheets of paper had to be thrown away. With electronic publications, these things don’t matter. “Pages” can be any size. White space can abound. Colors can be used on every “page”. That is, unless the viewer wants to print a copy.