Baldur's Gate: Enhanced Edition

Much of the game retains the original setting of Baldur's Gate and its expansion - that of the Forgotten Realms continent of Faerûn, the city of Baldur's Gate and the locations south of it within the regions of the Sword Coast and the Western Heartlands, including Beregost, Nashkel, Durlag's Tower and Candlekeep. The main story, too, is still retained - the player creates a character and takes them across the game's setting to investigate the iron crisis that is plunging Baldur's Gate towards a war with the neighbouring nation of Amn, uncovering it as the work of the game's main villain, Sarevok. All of the original characters that can join the player's party, and the quests that can be undertaken from both the main game and the expansion, still present within the remaster. The Enhanced Edition adds four non-player characters (NPCs) that can join the party, with three incorporating standalone story-lines (an element used with NPCs in Baldur's Gate II) of which two feature new locations.
The standalone arena adventure created for the remaster, The Black Pits, features a story set before the main events of Baldur's Gate, in which players create their own party of adventurers, in a similar fashion to that of the Icewind Dale series, and undertake battles in an area situated in a small portion of the Underdark, though there is little to do in terms of exploration except for the holding cells the party can move around within.

The Black Pits

Prior to the events of Baldur's Gate, a colony of Duergar dwarves is defeated by a mad drow sorcerer named Baeloth, who imprisons them and forces them to create an entertainment complex of his own design within the Underdark. Through his complex, the Black Pits, Baeloth assumes the title of "Baeloth the Entertainer", and draws in living creatures, monsters and adventurers from throughout the realms, either by invitation or forcefully capturing them, and pitting them against each other for loot. All who are brought to the Pits are imprisoned under the effects of a geas and cannot escape, eventually being killed during one of Baeloth's matches, with the exception of a champion, who was pitted against Baeloth himself after winning all their matches, but dying against the sorcerer. Baeloth's latest victims, a party of six adventurers (whose origins and past remain a mystery), survive their qualifying match and find themselves coerced into fighting in the Black Pits, learning that the drow is aided by a djinn named Najim, while their holding cells include several prisoners forced to operate as merchants, and a beholder who offers advice on the matches the party encounter.
Over time, with each successful match, Baeloth becomes increasingly frustrated at their survival against the tougher monsters he brings in, while some of merchants express support for their victories, along with hope that they may become free. Eventually, after becoming champions of the Pits, Baeloth decides to take the group on himself, expecting to defeat them and eliminate them so as to provide the crowds with some new fighters to root for. However, the match ends with Baeloth defeated himself and his geas on all of the complex's prisoners lifted. Najim, grateful of his freedom, helps the party escape, knowing that the duergar clan they freed will see them as outsiders and not accept them. The party swiftly leave by a portal, and enjoy their freedom soon afterwards.