\begin{tcbposter}[
  coverage = {spread,
    boxsep = 10pt,
  },
  poster   = {showframe=true,
    columns=4,
    rows=2,
  },
  boxes    = {
    colback=white,
    fit,
    fit basedim=10pt,
    before upper={\parindent10pt\noindent},
    frame code={\ifodd\thepage\node at (frame.south east) {\thepage};\else \node at (frame.south west) {\thepage};\fi\stepcounter{page}},
  },
]

\posterbox[
  before upper={\parindent0pt},
  ]{name=seventh,column=1,row=1,span=1,rowspan=1}{
  \subsubsection{\Glsfmtplural{weapon}}
  \glsdesc{weapon}.
  \rotatebox{-90}{\noindent\begin{minipage}{.40\textheight}
  \small
  \commonWeaponsChart
  \end{minipage}}
}

\posterbox[tikz={rotate=180}]{name=tenth,column=2,row=1,span=1,rowspan=1}{
  \subsubsection{\Glsfmttext{armour}}
  \glsdesc{armour}
  \par
  \vspace{1em}
  \subsubsection{\Glsfmtlong{dr}}
  \glsdesc{dr}
  \par
  \vspace{1em}
  \subsubsection{\Glsfmttext{covering}}
  \glsdesc{covering}
  {\footnotesize\commonArmourChart}
}

\posterbox[tikz={rotate=180}]{name=eleventh,column=3,row=1,span=1,rowspan=1}{
  \subsubsection{\Glsfmttext{projectiles}}
  \glsdesc{projectiles}
}

\posterbox[tikz={rotate=180}]{name=sixth,column=4,row=1,span=1,rowspan=1}{
  \subsubsection{\Glsfmttext{downtime}}
  \glsdesc{downtime}.
}

\posterbox{name=second,column=1,row=2,span=1,rowspan=1}{
  \begin{center}
    \subsubsection{\Huge BIND}
    \par
    \vspace{3\baselineskip}
    \subsubsection{The Rules-Light RPG}
    \par
    \vspace{3\baselineskip}
    \hint{(it weighs 5 grams!)}
  \end{center}
}

\posterbox{name=fifteenth,column=2,row=2,span=1,rowspan=1}{
  \subsubsection{\Glsfmttext{witchcraft}}
  \glsdesc{witchcraft}
}

\posterbox{name=fourteenth,column=3,row=2,span=1,rowspan=1}{
  \subsubsection{\Glsfmtplural{interval}}
  \glsdesc{interval}
  {\footnotesize\manaRegenChart}
}

\posterbox{name=third,column=4,row=2,span=1,rowspan=1}{
  \subsubsection{\Glsfmtplural{swarm}}
  \glsdesc{swarm}
}

\end{tcbposter}