BOOBY TRAPS

This Stratagem is used after both sides have
deployed, but before the first battle round begins.
Secretly pick a single ruin or Sector Mechanicus
structure that is not currently occupied by any
models, and write it down. The first time any
model moves within 1" of that terrain feature,
they trigger booby traps and their unit suffers
D3 mortal wounds (D6 if they Advanced this
turn).
In addition, roll a D6: on a 4+ that terrain
feature is now classed as dangerous terrain.