Function resist

src/zap.c:6099–6158

}

int
resist(struct monst *mtmp, char oclass, int damage, int tell)
{
    int resisted;
    int alev, dlev;

    /* fake players always pass resistance test against Conflict
       (this doesn't guarantee that they're never affected by it) */
    if (oclass == RING_CLASS && !damage && !tell && is_mplayer(mtmp->data))
        return 1;

    /* attack level */
    switch (oclass) {
    case WAND_CLASS:
        alev = 12;
        break;
    case TOOL_CLASS:
        alev = 10;
        break; /* instrument */
    case WEAPON_CLASS:
        alev = 10;
        break; /* artifact */
    case SCROLL_CLASS:
        alev = 9;
        break;
    case POTION_CLASS:
        alev = 6;
        break;
    case RING_CLASS:
        alev = 5;
        break;
    default:
        alev = u.ulevel;
        break; /* spell */
    }
    /* defense level */
    dlev = (int) mtmp->m_lev;
    if (dlev > 50)
        dlev = 50;
    else if (dlev < 1)
        dlev = is_mplayer(mtmp->data) ? u.ulevel : 1;

    resisted = rn2(100 + alev - dlev) < mtmp->data->mr;
    if (resisted) {
        if (tell)
            shieldeff_mon(mtmp);
        damage = (damage + 1) / 2;
    }

    if (damage) {
        mtmp->mhp -= damage;
        if (DEADMONSTER(mtmp)) {
            if (gm.m_using)
                monkilled(mtmp, "", AD_RBRE);
            else
                killed(mtmp);
        }
    }