1. Ships cannot exceed 75 broadside guns for each side making it in a total of 150 broadsides in maximum that can be used but can be customized in any way possible.
2. Magic is common but the stronger the spell the more consequences and Drawbacks it has... so use those spells sparingly but weaker versions of the spells can be used more often.
3. Keep it balanced, if the battle seems unfair to ask the person your against to tone it done a bit.
4. In terms of customization, as long it's not too overpowered you can use what you want.
5. If you decide to add a city, make sure to add it location to the known world.
6. Have fun... do whatever that suits your style.
