DOS RPG Test

#include <iostream>
#include <string>
#include <cstdlib>
#include <ctime>
#include <chrono>
#include <thread>
using namespace std;
float exp, pdmg, mdmg, nmdmg;
int decision, mhp, php, itm, gmvr;
int pot, clns, tp, usg;
void attack(),defend(),item(),dn(),run(),spell();
void delay(int millisecond), crit();
int main() {

    srand (time(NULL));
    pdmg = rand() % 25 + 5;
    mdmg = rand() % 20 + 15;
    nmdmg = rand() % 10 + 5;
    mhp = rand() % 35 + 65;
    php = 100;
    exp = rand() % 15 + 35;
    pot = rand() % 15 + 35;

    cout << "You encounter an orc, in the middle of the dungeon.\n";
    delay(1000);
    cout << "What do you do?\n";
    delay(1000);
    cout << "HEALTH: " << php << " MONSTER HEALTH: " << mhp;
    delay(500);
        bool condition = true;
    while (condition) {
    cout << "\n\n Attack (1)\n Defend (2)\n Item (3)\n Spell (4)\n Do nothing (5)\n Run away (6)\n";
    cin >> decision;
    switch (decision) {
        case 1:
            attack();
            break;

        case 2:
            defend();
            break;

        case 3:
            item();
            break;

        case 4:
            spell();
            break;
        case 5:
            dn();
            break;

        case 6:
            run();
            break;
            }
        if (mhp <= 0) {
        cout << "\n Orc has been defeated! gained " << exp << " xp.";
        return 0;
        }
    if (php <= 0) {
        cout << "\n Game Over. Would you like to try again?\n";
        string gmvr;
        cin >> gmvr;
        }
    if (mdmg > 35) {
        crit();
        break;
    }
    }
}
void attack() {
                cout << "You attack the orc, dealing " << pdmg << " damage.\n";
            mhp = mhp - pdmg;
            php = php - mdmg;
            delay(500);
            cout << "HEALTH:  " << php << " MONSTER HEALTH:  " << mhp;
            }
void defend() {
                cout << "You defend the orc's attack. You take " << nmdmg << " damage.\n";
                php = php - nmdmg;
                delay(500);
                cout << "HEALTH:  " << php << " MONSTER HEALTH:  " << mhp;
    }
void item() {
    cout << "What item would you like to use?\n";
    cout << "Potions (1)\n Cleansers (2)\n Teleport Scroll (3)\n";
    cin >> itm;
    switch (itm) {
        case 1:
            if (php == 100) {
                cout << "You are at full health.\n";
                break;
            }
            else if (php >= 75) {
                cout << "You drank a potion, healing " << pot << " health.\n";
                php = php + pot;
                delay(500);
                cout << "The orc attacks you while you were drinking the potion, dealing " << mdmg << " damage.\n";
                delay(500);
                php = php - mdmg;
                cout << "HEALTH: " << php << " MONSTER HEALTH: " << mhp;
                break;
            }
            else if (php <= 75) {
                cout << "You drank a potion, healing " << pot << " health.\n";
                php = php + pot;
                delay(500);
                    cout << "HEALTH: " << php << " MONSTER HEALTH: " << mhp;
                    break;

            }
        case 2:
            cout << "You cant use that right now.\n";
            delay(500);
            break;

        case 3:
            cout << "You cant use that right now.\n";
            delay(500);
            break;

    }
}
void spell() {

}
void dn() {
}
void run() {
}
void crit() {

}
void delay(int millisecond)
{
        std::this_thread::sleep_for(std::chrono::milliseconds(1000));
}