diff --git a/plugin/offside.vim b/plugin/offside.vim
new file mode 100644
index 0000000..0644d5c
--- /dev/null
+++ b/plugin/offside.vim
@@ -0,0 +1,23 @@
+function! s:InnerOffside() " {{{
+  let l:line = line('.')
+  let l:indent = indent(l:line)
+  for l:start in range(l:line, 0, -1)
+    if indent(l:start) <# l:indent
+      break
+    endif
+  endfor
+  for l:end in range(l:line, line('$') + 1)
+    if indent(l:end) <# l:indent
+      break
+    endif
+  endfor
+  return (l:start + 1) . 'GV' . (l:end - 1) . 'G'
+endfunction " }}}
+
+
+vnoremap <expr> <Plug>InnerOffside <SID>InnerOffside()
+
+if !hasmapto('<Plug>InnerOffside')
+  vmap <unique> <silent> io <Plug>InnerOffside
+  onoremap <unique> <silent> io :normal vio<cr>
+endif