Greetings and salutations, over the years as a Dungeon Master and Amateur Writer I have observed many new people to the hobby of roleplaying feeling they are ready to move beyond the beginners prewritten adventures ask just how to begin designing an adventure or a setting of their own.
While there are many methods available the effectiveness of which depending exactly what the Dungeon Master desires I will be creating a small series of short articles and videos focusing on Top Down and Bottom Up design with later examples of their use as I create my own world setting.

These two design methods are very similar and simple in concept  and focus more on the order of how things are created than the method of creation but each has its own advantages and disadvantages and in practice are bested used in combination than relying on either of them entirely.

Top Down Design: The Basic Principle

Top Down Design explained in its simplest form is this: Beginning at the highest level design each element moving a step lower each time.
In practice for example: a space setting a designer may begin at a galactic level deciding upon how many solar systems are within the galaxy, what empires if any span this galaxy.

Of course this is a very simple example that does not go into fine detail or down to the bottom level but its easy to observe the premise.

This can also be used on a smaller scale so if you wished to design a city for example:

1.  Design or take an existing city map that has no features listed on it.
2.  Decide upon any locations of districts within the city and their basic properties.
3. Focus next on its government, laws and associated bodies of power such as the guard or the military including key figures.
4. Flesh out each district in turn in regards to businesses, problems and key figures. 

Advantages And Disadvantages

The main advantages of using the Top Down Design approach are:

• Builds the overall setting in moderate detail allowing for play to move between areas or begin in different locations with more ease.
• Results in expansive notes regarding key locations, figures or laws even if they are footnotes or just names aiding further development and bookkeeping.
• Easier to keep design choices within the world consistent.  
• Leaves room for later expansion as new locations can be added to existing areas where the setting has not been fleshed out.
• Best used for creating settings that are intended to be used for long campaigns, repeatedly or across different locations and games that involve expansive travel such as Rogue Trader. 

The main disadvantages of using the Top Down Design approach are:

•  Requires advanced preparation before play begins and depending on scope of setting can be very time consuming. Especially if the level of detailed required for each area is unknown which can result in necessary areas been devoid of fine details when required.
• Lends itself to a encyclopaedic nature of world building which can result in far too much time been spent on unnecessary work in areas players will never encounter. This can also make it difficult for those unfamiliar with the setting to use it in their own games or create adventures for the setting due to amount of lore that dungeon masters need to be familiar with.

I hope this little article has helped with beginning understanding Top Down Design, in our next article we'll be taking a look at Bottom Up Design.