// genodds increases once you've spent more than 500 turns in Hell.

    if (one_chance_in(genodds))

    if (x_chance_in_y(5, genodds))

// This function is now only called about once every 5 turns. (Used to be
// every turn independent of how much time an action took, which was not ideal.)
// To arrive at spawning rates close to how they used to be, replace the
// one_chance_in(value) checks with the new x_chance_in_y(5, value). (jpeg)

        && one_chance_in((you.char_direction == GDT_DESCENDING) ? 240 : 8))

        && x_chance_in_y(5, (you.char_direction == GDT_DESCENDING) ? 240 : 8))

    // Place Abyss monsters.
    if (you.level_type == LEVEL_ABYSS && one_chance_in(5))

    // Place Abyss monsters. (Now happens regularly every 5 turns which might
    // look a bit strange for a place as chaotic as the Abyss. Then again,
    // the player is unlikely to meet all of them and notice this.)
    if (you.level_type == LEVEL_ABYSS)

    if (you.level_type == LEVEL_PANDEMONIUM && one_chance_in(50))

    if (you.level_type == LEVEL_PANDEMONIUM && one_chance_in(10))

    {
        const long old_synch_time = you.synch_time;

        // Call spawn_random_monsters() more often than the rest of
        // handle_time() so the spawning rates work out correctly.
        if (old_synch_time >= 150 && you.synch_time < 150
            || old_synch_time >= 100 && you.synch_time < 100
            || old_synch_time >= 50 && you.synch_time < 50)
        {
            spawn_random_monsters();
        }
    }