At line 306 in tbaMUD 3.63's act.item.c:

   /* "get all" gets something in the dark or while blind, when winning */  
    /* a dex plus level check against twenty times the average dexterity */

      if ((CAN_SEE_OBJ(ch, obj) || (GET_DEX(ch) + GET_LEVEL(ch)) > rand_number(1,220))
         && ((dotmode == FIND_ALL) || isname(arg, obj->name))) {
	found = 1;
	perform_get_from_room(ch, obj);
      }