In this step, I'm going to show you the Common Events you need.
You'll need 4 different Common Events. Two for each system.
CMine-A and CMine-B will be almost the same, while the GMite events will be amazingly simple with one difference between them.
Create 2 Variables. One called "Mining" and one called "Gyromite".
Now, create a Common Event and call it "Mining". For this, you're going to put at the top an event that will say "Control Variables: [0005: Mining] = Random No. (1...5)". To do this, go to Event Commands and click "Control Variables" on Page 1. In the "Variable" box, make the box next to the bit that says "Single" say "0005: Mining", put the Operation to "Set" and for Operand, click the box that says "Random" and make the two boxes next to that say "1" and "5".
Now create a Conditional Branch for the Variable "Mining" and make it equal to 1.
Under this branch, make some text say "Found one Small Crystal!" and create a Change Item event to add one Small Crystal to your inventory. Now add the "Erase Event" command.
Now repeat this process, but make each subsequent Conditional Branch for each different Crystal.
For the 5th Conditional Branch, create text that says "You found nothing" and make the "Erase Event" command.
Now copy the "Mining" Common Event and edit it as follows.
First, rename this Common Event to "Mining Royal".
Now edit the top event to say "Control Variables: [0005: Mining] = Random No. (1...9)".
With this, just Copy 2 conditional branches to fill up the number spaces and edit the Conditional Branches to equal 6 and 7.
Now create 2 new Conditional Branches where the Variables equal 8 and 9. For these, you're going to add text to say "Found one Gyromite!" and "Found one Royal Crystal!".
Again, add in the "Change Items" command to add these items to your inventory in their respective branches. Now you'll have the 9 Conditional Branches you need.
Finally, you're going to create the GMite Mining events.
Do the same thing you did with the Crystals, but this time so they give you GMites.
Create a Common Event called "Geomite Mining".
Like you did with the Crystals, create this event "Control Variables: [0005: Gyromite] = Random No. (1...3)".
Now create a Conditional Branch for the "Gyromite" Variable and make it equal 1.
Add text that says "You found nothing" and add the "Erase Event" command.
Now create another Conditional Branch that makes "Gyromite" equal 2. Add text that says "Found one Gyromite!" and add the Erase Event command.
Next, you guessed it, create the same Conditional Branch as above but edit it so you find a Geomite instead.
For the final Common Event, you're just going to do the same as above but make 2 branches instead.
Copy the Geomite Mining event into the next space and call it "Gyromite Mining".
Now create this "Control Variables: [0005: Gyromite] = Random No. (1...2)" and delete the Conditional Branch that lets you find the Geomite.
Now you've created all the Common Events you need, it's now time to put them on the map.