What is causing this not to work?

Question

It keeps saying unused variables for: Dam HP and Luck
int HP;
int Dam;
int Luck;
HP==5;
Dam==2;
Luck==3;

cout << "Please Choose a class" <<endl;
cout << "Enter 1 for sword, 2 for bow, or 3 for magic"<<endl;

cout << "Sword, Bow, Magic" <<endl;
int y;
cin >> y;

if (y==1) cout << "Sword!" << "+3 damage!" << endl;
if (y==1) Dam+3;
if (y==2) cout << "Bow!" << "+2 damage!" << endl;
if (y==2) Dam+2;
if (y==3) cout << "Magic!" << "+4 damage - 2 health" << endl;
if (y==3) Dam+4;
if (y==3) HP-2;

Answer 1

Thanks!