Low-poly cave floor

With this model we will be starting with a cube primitive as the base. The scale of the X axis can then be changed to 50 in the Channel Box to represent a long pathway. This is a bit thin to walk along for my game, so I am going to change the Z scale to 40. The Y axis can be changed to a scale of 50 because we don't want it to look like the cave floor is floating. Change the Translate Y to -25 so the top of the modified cube is resting on the grid. It should look a bit like this now.

Now we have the base shape complete, we can move on to structuring it for player movement and thinking about where rubble and cave like deformations will take place. This will be changing the sub division depth and height in the attribute editor. Set the Width to 10 and depth to 3. The reasons for these numbers are: 10 is a nice even number which can give organic results. The 3 in width is a special number because you can see them as lanes.
In the first lane (The farthest from you) there will be mainly cave pillars which are a separate asset, cave ground deformations, gravel and rubble.

In the second lane (The middle lane) is the player movement track, this ground will not have any rubble or deformations on due to the fact that they will be a obstacle the character may not be able to pass. This lane is for the character and track only, the track can have obstacles like rocks that the player can pass, but rubble may obstruct this.

In the third and final lane is cave ground deformations and rubble in front of the player. After creating this, your model should look similar to this.

Before we add ground deformations, it will be a good idea to create a bevel/boarder around the outside of the shape so when we modify these tiles they don't affect the base shape. We can do this by using the insert edge loop parallel to the base edges creating a boarder like this .

Now this is done, I feel as if the 1st and 3rd lane are too wide, I can fix this by using the insert offset loop right in the middle to split them into 2 for a more organic look, this will also add extra detail into the model as we will have 2 more lanes for rubble and cave deformations. After this is done, edit that new edge loop and double click to select the whole new edge, drag it to the edge at about 1/3 of the length, insert another edge loop and place this with equal spacing to the other. I will leave the middle lane as it is so the player can move freely without obstructions. Here is what i am left with.

To edit this and make it more rugged like a cave, lets turn on soft selection by clicking the cursor icon on the left, under the soft selection drop down, click the tick. You can edit the radius and curve presets which will change how the tool will act. I used a radius of 3 and the default curve setting. To finish this off, select the modelling work space at the top left, go under the Mesh drop down on the top menu bar and select Triangulate, this is the finished model.