In-game, this will probably be the most commonly seen version of Secret Power if you use it in your everyday training.
The effect of using Secret Power in grass is a 30% chance of Poison

In-game, you will find this effect in the Tall Grass whenever you have to pass through it to progress
The effect of using Secret Power in tall grass is a 30% chance of Sleep

In-game, you will come to use this effect when you're battling on the beach or in the desert
The effect of using Secret Power in sand is a 30% chance of Lowering Opponent's Accuracy

In-game, this will probably be the second most commonly seen version of Secret Power due to the abundance of caves which utilise this Secret Power
The effect of using Secret Power in rocky terrain is a 30% chance of causing opponent to Flinch

In-game, there are many areas that utilise the MountainSide and you will have battles on it
The effect of using Secret Power in mountainous areas is a 30% chance of Confusion

In-game, you will find many areas covered in Marshland, if you can get a battle here, Secret Power works differently
The effect of using Secret Power in Marshland is a 30% chance of Lowering opponent's Speed

In-game, this commonly found Secret Power effect is found whilst you are surfing in water
The effect of using Secret Power in Water is a 30% chance of Lowering opponent's Attack

In-game, this will only be found in RSE when you have used Dive and are underwater
The effect of using Secret Power Underwater is a 30% chance of Lowering opponent's Defense

In-game, this will be found when battling on Snowy Terrain
The effect of using Secret Power in snow is a 30% chance of Freeze

In-game, this will be found when battling in Buildings, Roads, over Wi-Fi, and other surfaces
The effect of using Secret Power in buildings is a 30% chance of Paralysis