if(ftype >= DNGN_MINMOVE)

        if (ftype >= DNGN_MINMOVE)

            // Maybe place a raincloud
            // The rainfall area is 20 (5*5 - 4 (corners) -1 (center))
            // the expected number of clouds generated by a fixed chance per
            // tile is 20 * p = expected.
            // Say an invo of 27 gives expected 5 clouds

            // Maybe place a raincloud.
            //
            // The rainfall area is 20 (5*5 - 4 (corners) - 1 (center));
            // the expected number of clouds generated by a fixed chance
            // per tile is 20 * p = expected.  Say an Invocations skill
            // of 27 gives expected 5 clouds.

            int expected = div_rand_round(max_expected *
                                          you.skills[SK_INVOCATIONS], 27);

            int expected = div_rand_round(max_expected
                                          * you.skills[SK_INVOCATIONS], 27);

            if(x_chance_in_y(expected, 20))
            {

            if (x_chance_in_y(expected, 20))

            }