Note: This procedure involves editing a game file; create a backup copy of the file before proceeding. Use a text editor to edit the "rts_cfg.h" file in the game directory. Change the values for the following lines to "0.0" so they resemble:

float EASY_DAMAGE = 0.0;
float HARD_DAMAGE = 0.0;
Begin a game on the easy or hard difficulty setting to have shields that cannot be harmed by normal weapons.