Can you recommend some underrated kingdom building light novels?

Sure. 'Re:Monster' is an excellent choice. The story revolves around a character who is reincarnated as a goblin and uses his knowledge and skills to build up a goblin kingdom in a fantasy world. Also, 'The Rising of the Shield Hero' has elements of kingdom building as the main character, who is initially ostracized, gradually builds his own influence and territory within the kingdom.

One popular 'kingdom building' light novel is 'Overlord'. In this novel, a powerful player gets trapped in a game world and starts to build his own kingdom with various unique and powerful minions. Another great one is 'Log Horizon', which focuses on the players' efforts to create a functioning society within the game world. And 'Re:Monster' also has elements of kingdom building as the protagonist, a reincarnated goblin, works towards creating a powerful goblin kingdom.

Another good 'kingdom building light novel' is 'Re:Monster'. The protagonist is reincarnated as a goblin in a fantasy world and uses his knowledge from his previous life to build a powerful goblin kingdom. It has an unique take on the genre with lots of action and growth elements.

One popular one is 'Overlord'. It features a powerful sorcerer who gets trapped in a game world and begins building his own kingdom. Another is 'Re:Monster' which has an interesting take on the isekai genre with the protagonist being reincarnated as a goblin and working towards building a great goblin kingdom. 'That Time I Got Reincarnated as a Slime' is also great. The slime protagonist gradually forms his own unique and powerful kingdom through various adventures and making allies.

Sure. 'The Chronicles of Narnia' is a great one. Narnia is a magical kingdom with its own rules and governance. Aslan is like the ultimate power in the kingdom, and the different creatures and humans in Narnia contribute to its unique kingdom - building elements.

One great kingdom building novel is 'The Wheel of Time' series. It has a complex world with different kingdoms and political systems that are built up over the course of the story. Another is 'A Song of Ice and Fire'. The various houses in Westeros are constantly vying for power and building their own mini - kingdoms within the larger realm. Also, 'Lord of the Rings' can be considered in a way. The kingdoms of Men, Elves, and Dwarves are all well - developed and their histories and rebuilding efforts are part of the story.

One of the popular kingdom building online novels is 'Mother of Learning'. It has an interesting take on the main character's journey in a world where power and kingdom - building play important roles. 'The Wandering Inn' is also a great choice. It shows how the main character starts from scratch and gradually builds up a place that could be considered a kingdom - like entity with its own rules, economy and social structure.

One underrated 'romance harem light novel' is 'A Sister's All You Need'. It has a unique take on the genre with its focus on a novelist and his relationships with the women around him. Another is 'How a Realist Hero Rebuilt the Kingdom', which has a bit of a harem element as the protagonist Kazuya Souma has female characters who support him in his quest to rebuild the kingdom. It's not as well - known as some others in the genre.

For beginners, 'Aria the Scarlet Ammo' is an underrated light novel. It has a simple yet engaging plot about a boy detective and a girl with special abilities. 'Date A Live' is also a good pick. It has an interesting concept of a boy having to date different spirits to save the world. The story is quite accessible and full of action and some romance. 'Re: Zero − Starting Life in Another World' is underrated in terms of being beginner - friendly. The main character's repeated resets and his growth throughout the story are easy to understand and follow.

One great kingdom building light novel is 'Overlord'. It features a powerful character who is transported into a game world and has to build his own kingdom. The story is full of strategic planning, interesting character interactions, and unique world - building elements.