Beamdog has already made admirable Android ports of the original Baldur's Gate RPG and its side-sequel Icewind Dale. Now you can get Baldur's Gate II, the continuation of the original that was first published way back in 2000 by none other than Bioware. Like the previous D&D RPGs, Baldur's Gate II costs ten dollars on the Play Store, which gets you the original game and all its expansion scenarios. The game is not restricted to tablets, though it will certainly be better played on one.
The core of BGII is Shadow Amn, which directly follows the story events of the original game. Though the game uses the Dungeons & Dragons tabletop world for its setting, rules, and even some of the game mechanics, the combat is in real time. Players can pause at any time to look around and plan out their strategy (which, incidentally, remains a staple of Bioware games more than a decade later). The primary campaign should last at least 50 hours, but playtime can stretch to more than 100 hours with the expanded content and side quests.
Baldur's Gate II on Android does offer in-app purchases, but they're completely optional and don't affect game balance. New party members (for when yours inevitably die) can be bought with real money, and a few cosmetic options are thrown in for good measure.