Consider this code
\documentclass{article}
\usepackage{lipsum}
\begin{document}
\setlength{\topsep}{3\baselineskip}
%\setlength{\partopsep}{3\baselineskip}
\hrulefill
\begin{enumerate}
\itemsep=20pt
\item \lipsum[2]
\item \lipsum[2]
\end{enumerate}
\end{document}
I know there is a possibility to change \itemsep with enumitem package, but I expect there is a method to change it locally without need of packages.
Why changing the length \topsep has no effect on vertical space before and after items unlike \partopsep length ( remove % before \setlength{\partopsep}{3\baselineskip}).
enumerateenvironment, not to the preamble. If you need them more frequently, wrap it into a new environment. When you put the patch into the preamble, it will be overwritten with every size changing command, like\normalsizeissued at the beginning of the document. – gernot Dec 31 '16 at 10:56\@listiby\@listI(capital i at the end) in the patch, then it might work when you put it into the preamble. But this will affect all list environments (in normal size), which might not be what you want. – gernot Dec 31 '16 at 10:58\@listiin a macro like this\def\ctopsep#1{ \let\orig@listi\@listi \def\@listi{\orig@listi\topsep=#1}}then I can use it with\ctopsep{3\baselineskip}when I need it – Salim Bou Dec 31 '16 at 11:08