\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/selten1975/fig1.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=playerthreecolor] (-1.515,-5.735) arc(135:315:0.375)
  -- (3.015,-2.265) arc(-45:135:0.375) -- cycle;
%% player 1 name Player~1
\def\playerone{Player~1}
%% player 2 name Player~2
\def\playertwo{Player~2}
%% player 3 name Player~3
\def\playerthree{Player~3}
%% level -2.0 node 1 player 1
\draw [line width=\treethickn] (0,2)
   ;
%% level 2.0 node 1 player 2 xshift -2.75 from -2.0,1 move R
\draw [line width=\treethickn,color=playeronecolor] (-2.75,-2)
   -- (0,2);
\draw (-1.375,0) node[left,xshift=-0.5mm,color=playeronecolor] {R\strut};
%% level 6.0 node 1 xshift -1.5 from 2.0,1 move R payoffs 1 1 1
\draw [line width=\treethickn,color=playertwocolor] (-4.25,-6)
   node[below,yshift=0.1\paydown,color=playeronecolor] {$\mathsf{1}\strut$}
   node[below,yshift=-0.9\paydown,color=playertwocolor] {$\mathsf{1}\strut$}
   node[below,yshift=-1.9\paydown,color=playerthreecolor] {$\mathsf{1}\strut$}
   -- (-2.75,-2);
\draw (-3.5,-4) node[left,xshift=-0.5mm,color=playertwocolor] {R\strut};
%% level 6.0 node 2 xshift 1.5 from 2.0,1 move L
\draw [line width=\treethickn,color=playertwocolor] (-1.25,-6)
   -- (-2.75,-2);
\draw (-2,-4) node[right,xshift=0.5mm,color=playertwocolor] {L\strut};
%% level 10.0 node 1 xshift -1.0 from 6.0,2 move R payoffs 4 4 0
\draw [line width=\treethickn,color=playerthreecolor] (-2.25,-10)
   node[below,yshift=0.1\paydown,color=playeronecolor] {$\mathsf{4}\strut$}
   node[below,yshift=-0.9\paydown,color=playertwocolor] {$\mathsf{4}\strut$}
   node[below,yshift=-1.9\paydown,color=playerthreecolor] {$\mathsf{0}\strut$}
   -- (-1.25,-6);
\draw (-1.75,-8) node[left,xshift=-0.5mm,color=playerthreecolor] {R\strut};
%% level 10.0 node 2 xshift 1.0 from 6.0,2 move L payoffs 0 0 1
\draw [line width=\treethickn,color=playerthreecolor] (-0.25,-10)
   node[below,yshift=0.1\paydown,color=playeronecolor] {$\mathsf{0}\strut$}
   node[below,yshift=-0.9\paydown,color=playertwocolor] {$\mathsf{0}\strut$}
   node[below,yshift=-1.9\paydown,color=playerthreecolor] {$\mathsf{1}\strut$}
   -- (-1.25,-6);
\draw (-0.75,-8) node[right,xshift=0.5mm,color=playerthreecolor] {L\strut};
%% level 2.0 node 2 xshift 2.75 from -2.0,1 move L
\draw [line width=\treethickn,color=playeronecolor] (2.75,-2)
   -- (0,2);
\draw (1.375,0) node[right,xshift=0.5mm,color=playeronecolor] {L\strut};
%% level 6.0 node 3 xshift -1.0 from 2.0,2 move R payoffs 3 2 2
\draw [line width=\treethickn,color=playerthreecolor] (1.75,-6)
   node[below,yshift=0.1\paydown,color=playeronecolor] {$\mathsf{3}\strut$}
   node[below,yshift=-0.9\paydown,color=playertwocolor] {$\mathsf{2}\strut$}
   node[below,yshift=-1.9\paydown,color=playerthreecolor] {$\mathsf{2}\strut$}
   -- (2.75,-2);
\draw (2.25,-4) node[left,xshift=-0.5mm,color=playerthreecolor] {R\strut};
%% level 6.0 node 4 xshift 1.0 from 2.0,2 move L payoffs 0 0 0
\draw [line width=\treethickn,color=playerthreecolor] (3.75,-6)
   node[below,yshift=0.1\paydown,color=playeronecolor] {$\mathsf{0}\strut$}
   node[below,yshift=-0.9\paydown,color=playertwocolor] {$\mathsf{0}\strut$}
   node[below,yshift=-1.9\paydown,color=playerthreecolor] {$\mathsf{0}\strut$}
   -- (2.75,-2);
\draw (3.25,-4) node[right,xshift=0.5mm,color=playerthreecolor] {L\strut};
%% iset 6.0,2 2.0,2 player 3
\node[inner sep=0pt,minimum size=\ndiam,draw=playeronecolor,fill=playeronecolor,shape=circle] at (0,2) {};
\node[inner sep=0pt,minimum size=\ndiam,draw=playertwocolor,fill=playertwocolor,shape=circle] at (-2.75,-2) {};
\node[inner sep=0pt,minimum size=\ndiam,draw=playerthreecolor,fill=playerthreecolor,shape=circle] at (-1.25,-6) {};
\node[inner sep=0pt,minimum size=\ndiam,draw=playerthreecolor,fill=playerthreecolor,shape=circle] at (2.75,-2) {};

% Player color legend
\begin{scope}[scale=1,shift={(-5.75,2.0)}]
\node[inner sep=0pt,minimum size=\ndiam,draw=playeronecolor,fill=playeronecolor,shape=circle] at (0,0) {};
\node[anchor=west] at (0.3,0) {Player~1};
\node[inner sep=0pt,minimum size=\ndiam,draw=playertwocolor,fill=playertwocolor,shape=circle] at (0,-0.625) {};
\node[anchor=west] at (0.3,-0.625) {Player~2};
\node[inner sep=0pt,minimum size=\ndiam,draw=playerthreecolor,fill=playerthreecolor,shape=circle] at (0,-1.25) {};
\node[anchor=west] at (0.3,-1.25) {Player~3};
\end{scope}

\end{tikzpicture}

                        \end{document}