// berserkers aren't really concerned about stealth

    // Berserkers aren't really concerned about stealth.

    // I assume that creatures who can sense invisible are very perceptive

    // I assume that creatures who can sense invisible are very perceptive.

    // critters that are wandering still have MHITYOU as their foe are
    // still actively on guard for the player, even if they can't see
    // him.  Give them a large bonus (handle_behaviour() will nuke 'foe'
    // after a while, removing this bonus.

    // Critters that are wandering but still have MHITYOU as their foe are
    // still actively on guard for the player, even if they can't see you.
    // Give them a large bonus -- handle_behaviour() will nuke 'foe' after
    // a while, removing this bonus.

            // monster is "hibernating"... reduce chance of waking

            // Monster is "hibernating"... reduce chance of waking.

// here's a question for you: does the ordering of mods make a difference?

// Here's a question for you: does the ordering of mods make a difference?

#ifdef WIZARD
    // Extreme stealthiness can be enforced by wizmode stealth setting.
    if (you.skills[SK_STEALTH] > 27)
        return (1000);
#endif

#ifdef WIZARD
    // If stealth is greater than actually possible (wizmode level)
    // pretend the player isn't there, but only for hostile monsters.
    if (proxPlayer && you.skills[SK_STEALTH] > 27 && !mons_wont_attack(mon))
        proxPlayer = false;
#endif

        // must be able to see each other
        if (!see_grid(mon->x, mon->y))

        // Must be able to see each other.
        else if (!see_grid(mon->x, mon->y))

// If prefer_named is true, named monsters (including uniques) are twice as
// likely to get chosen compared with non-named ones.

// If prefer_named is true, named monsters (including uniques) are twice
// as likely to get chosen compared to non-named ones.

                        // named monsters have doubled chances

                        // Named monsters have doubled chances.

// Altars as well as branch entrances are considered interesting
// for some monster types.
static bool _mon_on_interesting_grid(monsters *mon)
{
    // Patrolling shouldn't happen all the time.
    if (one_chance_in(4))
        return (false);
    const dungeon_feature_type feat = grd[mon->x][mon->y];
    switch (feat)
    {
    // Holy beings will tend to patrol around altars to the good gods.
    case DNGN_ALTAR_ELYVILON:
        if (!one_chance_in(3))
            return (false);
        // else fall through
    case DNGN_ALTAR_ZIN:
    case DNGN_ALTAR_SHINING_ONE:
        return (mons_holiness(mon) == MH_HOLY);
    // Orcs will tend to patrol around altars to Beogh, and guard the
    // stairway from and to the Orcish Mines.
    case DNGN_ALTAR_BEOGH:
    case DNGN_ENTER_ORCISH_MINES:
    case DNGN_RETURN_FROM_ORCISH_MINES:
        return (mons_species(mon->type) == MONS_ORC);
    // Same for elves and the Elven Halls.
    case DNGN_ENTER_ELVEN_HALLS:
    case DNGN_RETURN_FROM_ELVEN_HALLS:
        return (mons_species(mon->type) == MONS_ELF);
    // Killer bees always return to their hive.
    case DNGN_ENTER_HIVE:
        return (mons_species(mon->type == MONS_KILLER_BEE)
                || mons_species(mon->type == MONS_KILLER_BEE_LARVA));
    default:
        return (false);
    }
}
// If a hostile monster finds itself on a grid of an "interesting" feature,
// while unoccupied, it will remain in that area, and try to return to it
// if it left it for fighting, seeking etc.
static void _maybe_set_patrol_route(monsters *monster)
{
    if (monster->behaviour == BEH_WANDER
        && !mons_friendly(monster)
        && !monster->is_patrolling()
        && _mon_on_interesting_grid(monster))
    {
        monster->patrol_point = coord_def(monster->x, monster->y);
    }
}

    _maybe_set_patrol_route(monster);

    // move the monster:

    // Move the monster.

            return false;

            return (false);

    int  dist   = grid_distance(you.x_pos, you.y_pos, mon->x, mon->y);

                       // only seen through glass walls

#ifdef WIZARD
                    // Wizmode skill setting enforces hiddenness.
                    || you.skills[SK_STEALTH] > 27 && dist > 2
#endif
                       // Only seen through glass walls?

    int  dist   = grid_distance(you.x_pos, you.y_pos,
                                mon->x, mon->y);

                // we prefer prefixes over partial matches

                // We prefer prefixes over partial matches.