Problem becomes visible when a given Palantír is used to duplicate an effect of other Palantír.
Is a corruption check that happens as last action listed in Palantír cards text an effect of the Palantír?
If so, should a bearer of Palantír of Osgiliath, that taps it to duplicate the effect of Palantír of Minas Tirith, make two corruption checks (one from Palantír of Osgiliath, other from Palantír of Minas Tirith)?
Proposed regulation:
The following list contains texts of Palantíri that create an effects for which an ability of using a/this Palantír is required. The underlined fragments of texts are effects of a using a/this Palantír. Not all Palantíri are listed, because some of them do not create such effects.
Palantír of Amon Sûl (METW version) wrote:Unique. Palantír. If the bearer's company is ever below 2 characters and the company moves, discard the Palantír. 5 marshalling points if stored in a Haven . With its bearer able to use a Palantír, tap Palantír of Amon Sûl to look at your opponent's hand or tap it to use the abilities of either the Palantír of Annúminas or the Palantír of Elostirion if either one is in play. Bearer makes a corruption check.
Palantír of Annúminas (METW version) wrote:Unique. Palantír. With its bearer able to use a Palantír, tap Palantír of Annúminas to search through your play deck and discard pile for a sage only card. Put this card in your hand. Reshuffle your play deck. Bearer makes a corruption check. The Palantíri came from beyond Westernesse, from Eldamar.-LotRIII
Palantír of Minas Tirith (METW version), (MELE version) wrote:Unique. Palantír. Playable only at Minas Tirith. With its bearer able to use a Palantír, tap Palantír of Minas Tirith to look at the top five cards of your play deck; shuffle these 5 cards and return them to the top of your play deck. Do the same to your opponent's play deck. Bearer makes a corruption check.
Palantír of Orthanc (METW version), (MELE version) wrote:Unique. Palantír. Playable only at Isengard. With its bearer able to use a Palantír and with at least 5 cards in your play deck, tap Palantír of Orthanc to choose one card from your discard pile to place in your play deck (reshuffle the play deck). Bearer makes a corruption check. 'The Stones of Seeing do not lie...'-LotRV
Palantír of Osgiliath (METW version) wrote:Unique. Palantír. If the bearer's company is ever below 4 characters and the company moves, discard. 5 marshalling points if stored in a Haven . With its bearer able to use a Palantír, tap Palantír of Osgiliath to force the discard of any hazard permanent-event or to duplicate the effect of any Palantír in play. Bearer makes a corruption check. The chief and master of these was under the Dome of Stars at Osgiliath before its ruin.-LotRIII
Palantír of Amon Sûl (MELE version) wrote:Unique. Palantír. If the bearer's company is ever below 2 characters and it moves, discard this item. With its bearer able to use a Palantír, tap Palantír of Amon Sûl to look at your opponent's hand or tap it to use the abilities of either minion Palantír of Annúminas or minion Palantír of Elostirion if either one is in play. Bearer then makes a corruption check. 5 marshalling points if stored at Barad-dûr.
Palantír of Annúminas (MELE version) wrote:Unique. Palantír. With its bearer able to use a Palantír, tap Palantír of Annúminas to take a sage only card from your play deck and/or discard pile into your hand. Reshuffle your play deck. Bearer then makes a corruption check. '...the Men of Westernesse were diminished, and their city, Annúminas...fell into ruin...'-LotRII
Palantír of Elostirion (MELE version) wrote:Unique. Palantír. Playable at The White Towers. Discard if the bearer moves. If the bearer is a sage: your hand size increases by one and the bearer is able to use this Palantír this turn if he taps. With its bearer able to use a Palantír, tap Palantír of Elostirion to draw a card. Bearer then makes a corruption check.
Palantír of Osgiliath (MELE version) wrote:Unique. Palantír. If the bearer's company is ever below 4 characters and it moves, discard this item. With its bearer able to use a Palantír, tap Palantír of Osgiliath to force the discard of any hazard permanent-event or to duplicate the effect of any minion Palantír in play. Bearer then makes a corruption check. 5 marshalling points if stored at Barad-dûr.