Legendary items are hidden within the tomb, including the artifacts of the Trickster Gods. These items are powerful but come with madness flaws. The Tomb of Annihilation PDF lists the properties of items like the Staff of the Forgotten One. When a player attunes to these, the DM needs to secretly inform them of the flaw. Having the digital text open allows the DM to copy/paste the flaw to the player in a private message during a remote game, or print it out on a slip of paper. These items can corrupt the party, leading to inter-party conflict that is delicious to watch.