Width of nested tabularx environments
\documentclass{scrbook}
\usepackage{tabularx}
\makeatletter
\newcommand\cellwidth{\TX@col@width}
\makeatother
\begin{document}
\begin{tabularx}{\textwidth}{|X|X|X|}
\hline
{\begin{tabularx}{\cellwidth}{lX} %% <-- this does *not* work...
Name: & \hrulefill\\
Race: & \hrulefill\\
Profession: & \hrulefill\\
\end{tabularx}}&
\Large\textbf{Character Sheet} &
Empty so far\\
\hline
\end{tabularx}
\end{document}
You can't use @
-commands without protecting them between \makeatletter
and \makeatother
; it's best to do it beforehand. Note that the command is \TX@col@width
.