Yes and no.
As explained before, it does make in PL a differecne if you use the slower regional trains-mostly PolRegio or the PKP= labelled as ´INtercity´ faster trains. The latter Do need- in theory and principle, to be REServed for any trip. But I wont like to feed all those who board without. Seats are not marked at all for this-they may even be RES whilst train is moving on a longer trip.
PolRegio offers 3-day or all weekend ride-at-will rover tickets-as mini for ONLy PR or a little costlier with also some of the various other local operators. On a trip like this that would also involve at least KS=Koleje Slaskie and perhaps Kol. MaloPolskie. And several changes.
PKP=IC also offers a midweek rover, but one still needs to make a RES-at the windows- for any trip made. (multi przejazd).
I myself did the reverse of this trip last april-using an INterRail and got that seat REServ just a few mins before train went for just 1 PLN (20p.) And planned to get back to Wroclaw next week.
Assuming you post this to intend to use PKP (about 2 hourly IC trains on this route) and get a tiny lower cost:
I read an extensive overview from an insider on 3 levels of PKP-fares not too long ago-perhaps on this forum, more likely on the german ditto DSO, but could not find it back. It was likely added to another thread on these.
In essence it comes down to: whereas one can in theory, and perhaps enough knowledge of polski, flexible tickets, this cannot be done online and again one then still have to make that seat RES for train used.
Online one only can get-and often not long ahead (it seems nowadays anyone thinks one has to make such things monthes ahead=complete nonsense)- advance FIX tickets. It may very well work out cheaper to still buy the 2 vs. a more costly flex for whole distance+ RES.
I would simply only book 1st leg fix, and then when things are done in Kat go to relevant window and buy ticket for next trip-it hardly differs if that would be PKP or KS or KM or PR. PLUS that this leg-due to mining soil subsidence in the past-is so slow a BUS may even be faster and for these just turn up and buy ticket. Stations are side by side (in KRk back side of tunneled new main trains stop).
Overview of all timings/means and cost: e-podroznik.pl
Also much info on : trenopedia.com, run by a handicapped Polish train promotor.
