Function find_mac

src/worn.c:716–736

#undef altprop

int
find_mac(struct monst *mon)
{
    struct obj *obj;
    int base = mon->data->ac;
    long mwflags = mon->misc_worn_check;

    for (obj = mon->minvent; obj; obj = obj->nobj) {
        if (obj->owornmask & mwflags) {
            if (obj->otyp == AMULET_OF_GUARDING)
                base -= 2; /* fixed amount, not impacted by erosion */
            else
                base -= ARM_BONUS(obj);
            /* since ARM_BONUS is positive, subtracting it increases AC */
        }
    }
    /* same cap as for hero [find_ac(do_wear.c)] */
    if (abs(base) > AC_MAX)
        base = sgn(base) * AC_MAX;
    return base;
}

/*
 * weapons are handled separately;