Special Inbound/Outbound rules in Switzerland?

Anyways the fact that you get 3 I/O days kind of encourages taking more time than the absolut necessary in your home country. I have no idea why we’re getting 3, while much larger countries have to get by with only 2. 
A few weeks ago I used my remaining day for a day trip in Switzerland and in fact I was asked where I was going, but when I answered with a place within Switzerland the conductor didn’t say anything.

But then you can go pretty much in every direction to reach a border, how can anyone be sure you’re not leaving?

In the context of 3 days “own country” travel, clause 4.3.2 makes no sense.

How can someone only make 2 journeys over 3 days in a country the size of Switzerland?

It’s not clear from your original post what order your trips will be in, but Basel to Lucerne via Bern seems like an OK route to me.  There’s no constraint that says “you cannot have any fun or diversions between the border and your home”

In addition routing from Basel to Lucerne to visit home, to Bern to visit friends, and back home to Lucerne on the one day is travelling from the border to your home.  Not in a straight line, but it is from the border to home.

Will this result in using 2 “in country” days?  1 to get on the sleeper to Basel and then a second one to get home the next morning?

It would, if you’re not smart and break the journey in the app after midnight, but before you enter Switzerland. Or even in Basel-Bad which counts as Germany.

Someone mentioned here the 3 days were to be able to arrive with a sleeper and then travel on home. But every other country that you can reach by sleeper train would have the same problem

Thanks a lot for your answers so far!

I think the 3rd day is intended to be used if you happen to cross the boarder point by night train. The app then claims the departure day as an Inbound for some reason. But I’m not sure if ticket inspectors are able to reconstruct the whole trip history when checking the pass.

It will be the second scenario. According to ​@rvdborgt’s interpretation of the rule, I probably will need an additional ticket to be save because I won’t be travelling to a boarder point or airport by travelling from Lucerne to Bern and back.

It won’t. Basel SBB is considered as a boarder point.

Not necessarily. On this page Eurail explain how to avoid spending an inbound too many in this scenario:

https://www.interrail.eu/en/interrail-passes/interrail-mobile-pass/mobile-pass-faq/how-can-i-travel-back-home-by-night-train

The in/outbound is always linked to the date of the travel day with which it is activated, even if you only arrive in your home country the next morning. IMO that is a bug, or at least unexpected behaviour, and it has been a known issue for several years now, but Eurail are in no hurry to fix it (if ever).

I wouldn't see it that strict. IMO you can travel however you want, as long as it's from a border, airport or port.

If you arrive in Basel SBB by direct night train from Germany, then adding the direct night train to your pass WILL activate an inbound on the date of departure, which is the wrong date. You should split the journey in e.g. Freiburg or Basel Bad Bf (after midnight, but still abroad).

No Idea why this topic got marked as solved, it wasn't me…

I thought I read the rules for using the 3rd inbound somewhere on the SBB page but I couldn't find that paragraph anymore. Anyway given Interrail's workaround for night trains and the I/O rules of SBB, the 3rd Inbound day is somehow useless as ​@zagmund already wrote.

Did a quick test: i cannot reproduce that I need to use a Inbound for Basel Sbb (which was indeed the case earlier):

In the end, I probably will take  the risk and use my Inbound day for the round trip.

The in/outbound rules are the same everywhere, so there can't be any special SBB rules.