\documentclass[tikz,border=10pt]{standalone}
                        \IfFileExists{newpxtext.sty}{\usepackage{newpxtext,newpxmath}}{}
                        \linespread{1.10}
                        \usetikzlibrary{shapes}
                        \usetikzlibrary{arrows.meta}
                        \usepackage{graphicx}

                        \begin{document}

                        % TikZ code with built-in styling for game trees
% TikZ libraries required for game trees
\usetikzlibrary{shapes}
\usetikzlibrary{arrows.meta}

% Style settings for game tree formatting
\tikzset{
    every node/.append style={font=\sffamily\itshape},
    every text node part/.append style={align=center},
    node distance=1.5mm,
    thick
}

% Built-in macro definitions for game tree drawing
\newdimen\ndiam
\ndiam1.5mm
\newdimen\sqwidth
\sqwidth1.6mm
\newdimen\spx
\spx.7mm
\newdimen\spy
\spy.5mm
\newdimen\paydown
\paydown2.5ex
\newdimen\treethickn
\treethickn1.0pt
\definecolor{chancecolor}{RGB}{117,145,56}
\definecolor{playeronecolor}{RGB}{234,51,35}
\colorlet{playertwocolor}{blue}
\colorlet{playerthreecolor}{orange}
\colorlet{playerfourcolor}{purple}
\colorlet{playerfivecolor}{cyan}
\colorlet{playersixcolor}{magenta}

% Game tree content from /home/docs/checkouts/readthedocs.org/user_builds/gambitproject/checkouts/889/catalog/img/vonstengelforges2008/fig9.ef
\begin{tikzpicture}[scale=0.8
  , StealthFill/.tip={Stealth[line width=.7pt,inset=0pt,length=13pt,angle'=30]}]
% \draw [help lines, color=green] (-5,0) grid (5,-6);
\draw [line width=\treethickn,color=playeronecolor] (-7,-5.625) arc(90:270:0.375)
  -- (5,-6.375) arc(-90:90:0.375) -- cycle;
\draw [line width=\treethickn,color=playeronecolor] (1,-6.625) arc(90:270:0.375)
  -- (9,-7.375) arc(-90:90:0.375) -- cycle;
%% player 1 name 1
\def\playerone{1}
%% player 2 name 2
\def\playertwo{2}
%% level -2.0 node 1 player 0
\def\playerzero{Chance}
\draw [line width=\treethickn] (0,2)
   ;
%% level 2.0 node 1 player 2 xshift -7.0 from -2.0,1 move 1/3~(\frac{1}{3})
\draw [line width=\treethickn,color=chancecolor] (-7,-2)
   -- (0,2);
\draw (-3.5,0) node[left,xshift=-1mm,color=chancecolor] {1/3~($\frac{1}{3}$)\strut};
%% level 6.0 node 1 xshift 0.0 from 2.0,1 move x
\draw [line width=\treethickn,color=playertwocolor] (-7,-6)
   -- (-7,-2);
\draw (-7,-4) node[left,xshift=-0.5mm,color=playertwocolor] {x\strut};
%% level 12.0 node 1 xshift -1.0 from 6.0,1 move x payoffs 1 1
\draw [line width=\treethickn,color=playeronecolor] (-8,-12)
   node[below,yshift=0.1\paydown,color=playeronecolor] {$\mathsf{1}\strut$}
   node[below,yshift=-0.9\paydown,color=playertwocolor] {$\mathsf{1}\strut$}
   -- (-7,-6);
\draw (-7.5,-9) node[left,xshift=-0.5mm,color=playeronecolor] {x\strut};
%% level 12.0 node 2 xshift 1.0 from 6.0,1 move -x payoffs 0 0
\draw [line width=\treethickn,color=playeronecolor] (-6,-12)
   node[below,yshift=0.1\paydown,color=playeronecolor] {$\mathsf{0}\strut$}
   node[below,yshift=-0.9\paydown,color=playertwocolor] {$\mathsf{0}\strut$}
   -- (-7,-6);
\draw (-6.5,-9) node[right,xshift=0.5mm,color=playeronecolor] {-x\strut};
%% level 3.0 node 1 player 2 xshift -1.0 from -2.0,1 move 1/3~(\frac{1}{3})
\draw [line width=\treethickn,color=chancecolor] (-1,-3)
   -- (0,2);
\draw (-0.5,-0.5) node[left,xshift=-1mm,color=chancecolor] {1/3~($\frac{1}{3}$)\strut};
%% level 6.0 node 2 xshift -2.0 from 3.0,1 move -x
\draw [line width=\treethickn,color=playertwocolor] (-3,-6)
   -- (-1,-3);
\draw (-2,-4.5) node[left,xshift=-0.5mm,color=playertwocolor] {-x\strut};
%% level 12.0 node 3 xshift -1.0 from 6.0,2 move x payoffs 0 0
\draw [line width=\treethickn,color=playeronecolor] (-4,-12)
   node[below,yshift=0.1\paydown,color=playeronecolor] {$\mathsf{0}\strut$}
   node[below,yshift=-0.9\paydown,color=playertwocolor] {$\mathsf{0}\strut$}
   -- (-3,-6);
\draw (-3.5,-9) node[left,xshift=-0.5mm,color=playeronecolor] {x\strut};
%% level 12.0 node 4 xshift 1.0 from 6.0,2 move -x payoffs 1 1
\draw [line width=\treethickn,color=playeronecolor] (-2,-12)
   node[below,yshift=0.1\paydown,color=playeronecolor] {$\mathsf{1}\strut$}
   node[below,yshift=-0.9\paydown,color=playertwocolor] {$\mathsf{1}\strut$}
   -- (-3,-6);
\draw (-2.5,-9) node[right,xshift=0.5mm,color=playeronecolor] {-x\strut};
%% level 7.0 node 1 xshift 2.0 from 3.0,1 move y
\draw [line width=\treethickn,color=playertwocolor] (1,-7)
   -- (-1,-3);
\draw (0,-5) node[right,xshift=0.5mm,color=playertwocolor] {y\strut};
%% level 12.0 node 5 xshift -1.0 from 7.0,1 move y payoffs 1 1
\draw [line width=\treethickn,color=playeronecolor] (0,-12)
   node[below,yshift=0.1\paydown,color=playeronecolor] {$\mathsf{1}\strut$}
   node[below,yshift=-0.9\paydown,color=playertwocolor] {$\mathsf{1}\strut$}
   -- (1,-7);
\draw (0.5,-9.5) node[left,xshift=-0.5mm,color=playeronecolor] {y\strut};
%% level 12.0 node 6 xshift 1.0 from 7.0,1 move -y payoffs 0 0
\draw [line width=\treethickn,color=playeronecolor] (2,-12)
   node[below,yshift=0.1\paydown,color=playeronecolor] {$\mathsf{0}\strut$}
   node[below,yshift=-0.9\paydown,color=playertwocolor] {$\mathsf{0}\strut$}
   -- (1,-7);
\draw (1.5,-9.5) node[right,xshift=0.5mm,color=playeronecolor] {-y\strut};
%% level 4.0 node 1 player 2 xshift 7.0 from -2.0,1 move 1/3~(\frac{1}{3})
\draw [line width=\treethickn,color=chancecolor] (7,-4)
   -- (0,2);
\draw (3.5,-1) node[right,xshift=1mm,color=chancecolor] {1/3~($\frac{1}{3}$)\strut};
%% level 6.0 node 3 xshift -2.0 from 4.0,1 move -x
\draw [line width=\treethickn,color=playertwocolor] (5,-6)
   -- (7,-4);
\draw (6,-5) node[left,xshift=-0.5mm,color=playertwocolor] {-x\strut};
%% level 12.0 node 7 xshift -1.0 from 6.0,3 move x payoffs 0 0
\draw [line width=\treethickn,color=playeronecolor] (4,-12)
   node[below,yshift=0.1\paydown,color=playeronecolor] {$\mathsf{0}\strut$}
   node[below,yshift=-0.9\paydown,color=playertwocolor] {$\mathsf{0}\strut$}
   -- (5,-6);
\draw (4.5,-9) node[left,xshift=-0.5mm,color=playeronecolor] {x\strut};
%% level 12.0 node 8 xshift 1.0 from 6.0,3 move -x payoffs 1 1
\draw [line width=\treethickn,color=playeronecolor] (6,-12)
   node[below,yshift=0.1\paydown,color=playeronecolor] {$\mathsf{1}\strut$}
   node[below,yshift=-0.9\paydown,color=playertwocolor] {$\mathsf{1}\strut$}
   -- (5,-6);
\draw (5.5,-9) node[right,xshift=0.5mm,color=playeronecolor] {-x\strut};
%% level 7.0 node 2 xshift 2.0 from 4.0,1 move -y
\draw [line width=\treethickn,color=playertwocolor] (9,-7)
   -- (7,-4);
\draw (8,-5.5) node[right,xshift=0.5mm,color=playertwocolor] {-y\strut};
%% level 12.0 node 9 xshift -1.0 from 7.0,2 move y payoffs 0 0
\draw [line width=\treethickn,color=playeronecolor] (8,-12)
   node[below,yshift=0.1\paydown,color=playeronecolor] {$\mathsf{0}\strut$}
   node[below,yshift=-0.9\paydown,color=playertwocolor] {$\mathsf{0}\strut$}
   -- (9,-7);
\draw (8.5,-9.5) node[left,xshift=-0.5mm,color=playeronecolor] {y\strut};
%% level 12.0 node 10 xshift 1.0 from 7.0,2 move -y payoffs 1 1
\draw [line width=\treethickn,color=playeronecolor] (10,-12)
   node[below,yshift=0.1\paydown,color=playeronecolor] {$\mathsf{1}\strut$}
   node[below,yshift=-0.9\paydown,color=playertwocolor] {$\mathsf{1}\strut$}
   -- (9,-7);
\draw (9.5,-9.5) node[right,xshift=0.5mm,color=playeronecolor] {-y\strut};
%% iset 6.0,1 6.0,2 6.0,3 player 1
%% iset 7.0,1 7.0,2 player 1
\node[inner sep=0pt,minimum size=\sqwidth,draw=chancecolor,fill=chancecolor,shape=rectangle] at (0,2) {};
\node[inner sep=0pt,minimum size=\ndiam,draw=playertwocolor,fill=playertwocolor,shape=circle] at (-7,-2) {};
\node[inner sep=0pt,minimum size=\ndiam,draw=playeronecolor,fill=playeronecolor,shape=circle] at (-7,-6) {};
\node[inner sep=0pt,minimum size=\ndiam,draw=playertwocolor,fill=playertwocolor,shape=circle] at (-1,-3) {};
\node[inner sep=0pt,minimum size=\ndiam,draw=playeronecolor,fill=playeronecolor,shape=circle] at (-3,-6) {};
\node[inner sep=0pt,minimum size=\ndiam,draw=playeronecolor,fill=playeronecolor,shape=circle] at (1,-7) {};
\node[inner sep=0pt,minimum size=\ndiam,draw=playertwocolor,fill=playertwocolor,shape=circle] at (7,-4) {};
\node[inner sep=0pt,minimum size=\ndiam,draw=playeronecolor,fill=playeronecolor,shape=circle] at (5,-6) {};
\node[inner sep=0pt,minimum size=\ndiam,draw=playeronecolor,fill=playeronecolor,shape=circle] at (9,-7) {};

% Player color legend
\begin{scope}[scale=1,shift={(-9.5,2.0)}]
\node[inner sep=0pt,minimum size=\sqwidth,draw=chancecolor,fill=chancecolor,shape=rectangle] at (0,0) {};
\node[anchor=west] at (0.3,0) {Chance};
\node[inner sep=0pt,minimum size=\ndiam,draw=playeronecolor,fill=playeronecolor,shape=circle] at (0,-0.625) {};
\node[anchor=west] at (0.3,-0.625) {1};
\node[inner sep=0pt,minimum size=\ndiam,draw=playertwocolor,fill=playertwocolor,shape=circle] at (0,-1.25) {};
\node[anchor=west] at (0.3,-1.25) {2};
\end{scope}

\end{tikzpicture}

                        \end{document}