On Mar 28, 8:25*pm, Harald Gentexeater wrote:
I'm a warlord and I want to conquer a city, but their
defense is too strong for me and my men.

So we need another plan.I want to build a Trojan
Horse to be brought into the city.

How can I design a Trojan Horse???

As others have replied, use a CAD program.
Actual building is more complex. As I remember, the attackers
at Troy were mariners from an island cluster. They
would have used wooden boatbuilding techniques.

So, getting back on topic, rent the DVD of Mutiny on the Bounty,
and pay careful attention to the little DVD extra which is a
documentary of the boatwrights making a replica
vessel for the movie production. You'll need a sharp adze.