what is free-living gametophyte?
If it is to live freely without depending on sporophyte then in pteridophytes (Selaginella) this free-living gametophyte is dependent on sporophyte. How?

The free living gametophyte means that has free existence and is not depended on sporophyte for food and other components. In case of pteridophytes, the gametophyte is produced when spores fall on the substrate usually shady and cool places. These spores germinate and produce gametophyte. ​The gametophytes bear male and female sex organs called antheridia and archegonia. The male gametes released from the antheridia enters the archegonium and fuses with female gamete to form zygote. Zygote then grows and develops into sporophyte.