Somebody's house rule. Somebody else's heresy.
Each of these is a setting or a stated ruling, not an assumption. You settle it before the match, so nobody argues during it.
Three sixesTable setting
Some tables lose the whole turn on a third six. Some keep them. Ludoo treats it as a setting, because both tables exist and both are right. The rule
The sideways kickTable setting
Kicking across a lane rather than along it. Whether it reaches one square or the whole lane changes the game completely, so it is set before the match rather than argued during it. The rule
Adding a six to take somebodyLudoo ruling
A six may be added to the other numbers in your hand as one movement, and that movement is legal only if it lands on an opponent and takes them. It buys reach, not passage: the chain still walks every square, so a wall in the way stops it however well the numbers add up. The rule
Blocks and wallsSet by the rules in force
Two of your pieces on one square hold it. Whether anyone may pass a wall, and what happens when two meet, is set by the rules in force. The rule
Off the tableFixed
A die that bounces off is a die that did not count. The physics run on your phone and the server decides the outcome, so the same flick is the same result for everyone watching. The rule