\documentclass[a4paper,12pt,oneside]{memoir}
\usepackage{fontspec}
\usepackage{xunicode}
\usepackage{xltxtra}
\usepackage{polyglossia}
\setdefaultlanguage{russian}
\defaultfontfeatures{Mapping=tex-text, Scale=MatchLowercase}
\setmainfont{PT Serif}
\setmonofont{PT Mono}
\setmathrm{PT Serif}
\newfontfamily{\cyrillicfont}{PT Serif}
\newfontinstance\scshape[Letters=SmallCaps, Numbers=Uppercase]{PT Serif Caption}
\usepackage{hyperref}
\usepackage{indentfirst}
\usepackage[cm]{fullpage}
\usepackage{tabulary}
\usepackage{ifthen}
\pagestyle{empty}
\setcounter{secnumdepth}{0}
\setcounter{tocdepth}{2}

\newcommand{\weapon}[2]{
  \subsubsection{#1}
  #2\par
}
\newcommand{\calcminstrength}[1]{
  0%\RoundNum{\pgfmathparse{#1/1.1}}
}% or smth like that
\newcommand{\minstrength}[1]{\ifthenelse{\calcminstrength{#1} < 1}{1}{\calcminstrength{#1}}}
\newcommand{\weaponstats}[2]{%
  \begin{table}[h] \begin{tabulary}{\textwidth}{CC}%
  Price & #1 \\
  Weight & #2 \\
  Minimal Strength & \minstrength{#2}
  \end{tabulary}\end{table}
}
\newcommand{\meleestats}[3]{
  \begin{table}[h] \begin{tabulary}{\textwidth}{CC}
  AP/hit & #1\\
  AP/target hit & #2\\
  Damage & #3\\
  IUC (hit) & ???
  % Inaccurate Universal Charateristic -- some sort of DPS for the balancing needs
  % roughly is (10/AP per hit) * Damage, but really that's complicated
  % you see, Damage is smth like 1d10 + A + N, where N is a number and A is a variable which depends on another variable.. And IUC is two numbers:
  % minimal (10/AP per hit) * 1 + min(A) + N, maximal (10/AP per hit) * 10 + max(A) + N
  % Moreover, for ranged weapons there are reloading APs...
  \end{tabulary}\end{table}
}

\begin{document}
\chapter{Gear}
...

\weapon{Rock}{A common rock -- no more than 3\% of iron.}
\weaponstats{0}{1}
\meleestats{3}{4}{A}

...
\end{document}