bool destroyed = false;
    bool hostile_grid = false;

    destroyed = (chance == 0) ? false : one_chance_in(chance);
    hostile_grid = grid_destroys_items(grd(where));

    // Enchanted projectiles get an extra shot at avoiding
    // destruction: plus / (1 + plus) chance of survival.
    bool destroyed = (chance == 0) ? false :
        (one_chance_in(chance) && one_chance_in(item->plus));
    bool hostile_grid = grid_destroys_items(grd(where));