Bay 12 Games Forum

Major changes are probably going to be a pain for me, because they involve changing terrain type. Go ahead, though, don't let that discourage you; let the fact that you're not doing three minor actions discourage you. 

Anyways, there are two types of Major Changes.
One is "Terrain Change." It involves taking a single hex of any terrain type and turning it into a single hex of any other terrain type. Terrain types are deep water, shallows, swamp, plains, forest, hills, mountains, deserts, and tundras. No tundras currently exist. I can live with that, but feel free to add tundra if you wish.
The other is "Terrain Shift." This affects a region of up to three adjacent hexes of the same type, which turn into a similar terrain type. Use your good judgement--plains and deserts are similar, but deep oceans and mountains are not! I will reject any Terrain Shift which does not change terrain into similar types.

The biggest downside to Major Changes is that you lack control over the final result.

Minor changes are a bit subtler. They involve modifying a tile rather than completely replacing it. A minor change adds a single feature to the world. Such features include but need not be limited to:

Island: A small island or a few smaller islands is/are created in a specified hex
Lake: A small lake is created either in a specific hex or between two or three hexes.
Mineral Deposit: A very rich deposit of a specified mineral is created in a specified hex.
River: Choose a source, a mouth, and optionally a route it takes. Don't violate the laws of nature too much with this; a river which winds across the entire continent WILL be rejected.
Ruins: Ruins from a time before history, perhaps before any known race walked on the world, are placed in a hex.
Terrain Shift: As the major action, but affecting only a single tile (or perhaps less).
Volcano: A volcano is created. It may only be placed in mountains or oceans, or on islands, under typical conditions; if you want a desert or forest volcano, you'd best justify it first.

If you come up with another feature that you want to add, let me know and I'll probably approve of it.

Sometimes, you'll want to do something bigger. A massive ice sheet? A major river with branches across the world? An archipelago which stretches a hundred miles? A mysterious volcanic island? A lake fed by a river? All of these involve multiple actions.

If you want to, you may use multiple actions to create multiple features which are combined into one. Describe the actions used and the result expected; if I approve of it, you can do it.
You can also combine actions with other players for exceptionally large or complex features.