Method effect

crawl-ref/source/potion.cc:352–362

    // it always prompts. XX maybe add info to the prompt?

    bool effect(bool=true, int pow = 40, bool is_potion = true) const override
    {
        const bool was_attractive = you.duration[DUR_ATTRACTIVE] > 0;

        mprf(MSGCH_DURATION, "You feel %sattractive to monsters.",
             was_attractive ? "more " : "");

        const int dur = _scale_pot_duration((20 + random2(pow)/2), is_potion);
        you.increase_duration(DUR_ATTRACTIVE, dur);
        return true;
    }
};