Chrono Cross 

Easy Money:
Play at the roulette table in the Zelbess Casino. As the pointer is spinning,
pause the game when the pointer is between point south and west on the wheel. 

Finally, hold X and the pointer will land on north every time. 

Safe Bet On Roulette Game:
I recommend you practice the Roulette first before you go and blow all of you money.
Start with small bets and work your way up to the bigger amounts of money.
At the roulette table in the Zelbess Casino you can cause the pointer to land on north
every single time by following the steps. 

As the pointer is spinning PAUSE the game while the pointer is between
the South and West positions on the wheel.
Now press and hold the Action button and the pointer will land on North every single time 

Treasure Chest Trick:
Throughout the game, especially in the Viper Manor,
there are many decoy treasure chest which are actually enemies.
When you encounter them they tell you, you only have "one chance" to attack the correct
one to recieve the prize they have.
All you have to do to ensure yourself the prize is to randomly attack one.
If you do not choose the right one the first time, just "run away" and repeat.
You can do this as many times as you want at no cost. Enjoy! 

Easy way to beat Dario:
This is a very easy way to beat Dario and get Serge's most powerful weapon.
First you have to go battle the Black Dragon and use Fargo to steal the armor called
the "Black Plate".
Next equip the black plate on Serge after having beat all of the other dragons except
for the White Dragon.
To be able to fight Dario you have to battle Peppor and Solt where Garai once was.
After the battle they give you an item used to make Dario regain his memory.
One you have the item (again make sure that you have the Black Plate on serge,
and Riddle in your party) go to the tiny island to the northeast of the big island
called the Forbidden Island. Go in the hut and then battle Dario.
The battle should be semi-easy as all of Dario's magic when cast at Serge will heal him.
Once the battle is over you should receive the Masamune. Side Note: Dario has about 3800 hp.