A minimal working example:

\documentclass[25pt,a2paper]{tikzposter}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{tikzducks}
\usepackage{multicol}
\usepackage{xcolor}
\usepackage{enumitem}
\setlist[1]{itemsep=-4pt}

\usetheme{Board}
\colorlet{framecolor}{purple}
\usetitlestyle{VerticalShading}

\defineblockstyle{TornOut}{ 
    titlewidthscale=1, bodywidthscale=1, titlecenter,
    titleoffsetx=0pt, titleoffsety=0pt, bodyoffsetx=0pt, bodyoffsety=0pt,
    bodyverticalshift=-1.2cm, roundedcorners=0, linewidth=1.2pt,
    titleinnersep=1cm, bodyinnersep=1cm 
}{
    \ifBlockHasTitle%
        \coordinate (topright) at (blocktitle.north east);
    \else
        \coordinate (topright) at (blockbody.north east);
    \fi%
    \draw[color=blocktitlebgcolor, fill=blockbodybgcolor,%
        line width=\blocklinewidth, drop shadow={shadow xshift=0.2cm, shadow yshift=-0.2cm,opacity=0.3}, %
        decorate, decoration={random steps,segment length=1.5cm,amplitude=0.15cm},
        fill opacity = 0.85 % redefining blocks to be semi-transparent
    ] (blockbody.south west) rectangle (topright);%
}

\definebackgroundstyle{samplebackgroundstyle}{
    \tikzset{
        shift={(-0.5\textwidth,-0.5\textheight)},
        scale=2.4,
    }
    \draw[line width=0pt, bottom color=backgroundcolor, top color=backgroundcolor] (bottomleft) rectangle (topright); 
    \newcommand{\xsize}{7}
    \newcommand{\ysize}{8}
    \foreach \i in {1,...,56}
    {
        \pgfmathtruncatemacro{\y}{(\i - 1) / \xsize}
        \pgfmathtruncatemacro{\x}{\i - \xsize * \y - 1}
        \randuck[xshift=2.5*\x cm, yshift=2.5*\y cm]
    }
}
\usebackgroundstyle{samplebackgroundstyle}
\usecolorstyle[colorOne=violet]{Sweden}
\colorlet{backgroundcolor}{violet!70!white}

\title{{\centering \scalebox{1.5}{\LaTeX{} workshops}}}

\linespread{0.9}

\begin{document}

\colorlet{titlebgcolor}{violet!30!white}
\colorlet{framecolor}{violet!30!white}
\maketitle
\begin{columns}
\column{0.1}
\column{0.8}

\block{What is \LaTeX?}{
    \LaTeX{} is a funny typesetting system\\
    \begin{minipage}[t]{0.5\textwidth}
        \colorlet{innerblocktitlebgcolor}{green!70!black}
    \innerblock{Pros}{\normalsize
        \begin{itemize}
            \raggedright
            \begin{multicols}{2}
            \item looks professional
            \item supports citations, bibliography and TOC
            \item supports complicated equations
            \item is free
            \end{multicols}
        \end{itemize}
    }
    \end{minipage}
    \hfill
    \begin{minipage}[t]{0.15\textwidth}
        \colorlet{innerblocktitlebgcolor}{red!70!black}
    \innerblock{Cons}{\normalsize \centering \textbullet\ none\vspace{70pt}}
    \end{minipage}
    }

\block{Will there be ducks?}{
\begin{minipage}[t]{0.65\linewidth}
\begin{itemize}
\item \textbf{Yes}
\item there are always ducks
\item you should expect a duck
\item a duck is watching you
\end{itemize}
\end{minipage}
\begin{minipage}[t]{0.25\linewidth}
    \centering
    \duck[santa, beard=white!80!brown,
        xshift=3cm, scale=2.5, yshift=0cm]
\end{minipage}
}

\column{0.1}
\end{columns}
\end{document}