Here are several rules that came from Tues game.
JJ typing, Moving Walkers 40k6 pg 84
Difficult terrain affects Walkers just as it does Infantry, and only counts as dangerous terrain if it would do so for Infantry.
Context: I thought Walkers treated difficult terrain as dangerous. Rolled to see if Psyflemen was immobilized. Rolled a 1. Then Connor spoke up and asked me if I was rolled to see if it was immobilized. Said yes. He then informed me they moved like infantry. Always like playing against Connor. He's always teaching me something new. Must be stuck in 5th ed.
Declare Charge 40k6 pg 20
A unit can never declare a charge against a unit that it cannot reach, nor can it declare a charge a unit that it cannot see.
Context: Connor was moving some wraiths and said that since he cannot see the Psyflemen he cannot charge it. Was curious where this rule was for future use. He showed me the reference.
Go to Ground 40k6 pg 18, specifically Snap Firing while going to ground
A unit that has gone to ground cannot move, Run or charge. It can only fire Snap Shots when it wishes to shoot, and can fire Overwatch
Context: Yet another thing Connor taught me. He mentioned out of passing that a squad can snap fire when going to ground. Must still be stuck in 5th ed. Again, provided me the reference.