Concluding our board game week, we turn our attention to the tabletop equivalent of videogame downloadable content: the expansion. Sometimes an expansion feels like a lazy or cynical cash grab. Sometimes it’s a nice bonus but hardly essential. But sometimes, as in these cases, it’s so transformative that you should never play without it.

Castle Panic: The Wizard’s Tower is a wonderfully balanced enhancement to a base game that, for adult players at least, can often feel overly simplistic. It gives to the players by adding an entire new deck of cards which let you unleash magic rather than merely fight monsters. But it takes by unleashing three extra monsters from a selection of new opponents with some truly nasty and potentially devastating abilities.

These twin changes give the game more depth and require more thinking and planning about the tactics you use. There’s also an added element in that one of the towers you defend is replaced with the wizard tower and you can only use magic cards while it still stands – a change that means positional awareness becomes even more significant.

Machi Koro: Harbor Expansion brings together three of the most common additions in an expansion: support for an extra (fifth) player, additional cards, and changes to the rules. The new cards add a lot of strategy thanks to the way they fit and work together with each other and with the existing deck, giving a wider range of possible strategies. Meanwhile the rule change makes a huge difference: previously you could always buy one card of each type. Now all the cards are mixed together and you select from a ‘market’ of 10 random cards. It adds in what some would see as more luck and others would call more variety, but most importantly it makes it more of a challenge to react to events.

Carcassone: Inns & Cathedrals only brings a few seemingly minor twists and might seem poor value, but the subtle changes it makes are enough to improve the game while being simple enough that you can teach or learn the base game with these in place. The titular inns and cathedrals simply make roads and cities more valuable, but this does a great balancing job to the game. Meanwhile the giant meeple that’s worth double an ordinary meeple works so well in offering players the dilemma of using it offensively or defensively that it’s been reused in the base game of some spinoffs and rethemes such as the Star Wars version. Carcassone is certainly guilty of overdoing the expansions, but Inns & Cathedrals is enough of an improvement that it’s arguably a must-have.

What expansions have you played that left you never wanting to go back to the base game? Let us know!