Thunderstone Advance is my favourite deckbuilding game, and is has a dungeon theme. It is designed as a competitive game where obtaining victory points from monsters, heroes and items will decide the winner. Games I like the most tend to have a good solo game built in, and this does have a version in the rules, however I find it swings from too easy on standard level to impossible on difficult level. The main reason for this is that the standard level gives you a lot of time where the dungeon is not refilling itself to deckbuild, and the latter is just relentless in spawning monsters to the point you quickly cannot cope. There are some ways to combat this, one is to choose weapons and heroes which work to your advantage and give you the best combinations, and / or pick the easier monster sets. Another is to adapt some rules.
Solo Rules Variant
Set Up – I prefer to theme my dungeons and so will use three sets of monsters as the basic rules suggest one for each level, however I don’t simply select the sets of 10 level 1,2,3 monsters and shuffle them into a 30 card deck, as this produces no longer term difficulty scaling. I start by shuffling and discarding each of the three chosen monster decks down to 8 (leaving two of each in the box), and I then shuffle the level 1 cards and randomly remove 2, shuffling the remaining 6 as the opening part of the deck. I then randomly take 6 level 2 cards and add the 2 remaining level 1’s put aside and shuffle, placing these under the initial level 1 cards. I then take 6 level 3 cards, shuffle in the 2 level 2 cards put aside and shuffle these, placing these under the other cards you have already built. Finally take the last 2 level 3 monsters and shuffle in the thunderstone bearer or chosen boss and place these under all the other cards. This leaves you with a scaling deck of 25 cards (with the boss in the final 3 cards). This slightly smaller deck helps reduce game time and I feel improves balance a little.
Heroes Levelling Up – You can buy level 1 heroes but after that levels 2 and higher can only be obtained by paying experience, I have always felt the value of earning experience should be to level up heroes. You can level up one hero only each time you visit the village.
Monster Spawning – The most critical change is to adapt the dungeon spawn rules. The solo rules state when you defeat a monster you would normally either not deal a new one (standard level) or deal one anyway (hard level). I find a better balance is to have a decision to make after you defeat a monster. You can choose to either place the beaten monster in your discard pile as usual and earn the victory points, in which case you deal a new monster into the dungeon at the round end, or alternatively you can destroy the beaten monster to buy time, and you wont deal out a new monster and you will lose the victory points from it not being in your end deck (you still get the experience and resolve any aftermath). This gives you an ongoing decision, do I need the points or the gold the card gives you or do I need to stall the monsters right now. If no monster is defeated then spawn one as normal. The game can be so different depending on which monsters and village items are in play so any set up rules may need tweaking depending on combinations, but this one has better balance than the boxed rules.
Victory Conditions – A solo victory is achieved from killing the Guardian, this is the main aim and you are building the deck to complete this. Your secondary aim is to save the village, and you will do this by having more victory points in your end deck than the points of monsters that got through and attacked your village. A double success is the ultimate challenge, but sometimes you can pull off saving the village even when you let the end guardian survive. Managing which monsters to destroy and which ones to keep for victory points becomes important for saving the village.
I am currently playing the Worlds Collide set and Into the Abyss expansion, and really like the level 1 oozes, level 2 spiders and levels 2 and 3 doombringers. Taking oozes, level 2 and 3 doombringers and the last doomknight guardian boss is a great solo game. Spiders are also good for solo play as they have breach rules which can destroy your heroes, and so you must keep thinking ahead before they hit rank one, it makes for a very engaging fight.