This is a personal, largely spoiler free (or spoiler-vague) review of the Defense of the Arkham fan made scenario by Rei for Arkham Horror the Card Game.
Based on the DOTA video game, Defense of the Arkham has investigators fighting to take down towers of evil that have appeared in Arkham, while stopping waves of enemies that are heading towards the city to destroy it. A variety of guardian enemies defend the towers, and the locations in between are scattered with allies to find. While the scenario has some neat ideas, the elements of DOTA it's aping directly end up causing the scenario to suffer, especially at lower player counts.
Defense of the Arkham is a difficult scenario with a unique feeling of pushing towards an enemy location, while having to be careful to defend a location of your own. You need to take down the defenses on enemy locations before fighting a randomly selected guardian at them, and all through the map powerful story assets are hidden that can be won and used. The scenario plays out in stages - with the first stage having only enemies coming from one side to deal with, and the second stage opening up the map, causing enemies to spawn in from both sides. Enemies feel appropriately threatening, and those without hunter lead to interesting trade-offs, as even locations cleared of clues may need to be returned to to chase down enemies or cross the map. Combined with treacheries that attach to locations - and may even penalize you for not triggering their bad effect - this leads to the feeling of the map being a minefield, and positioning mattering.
This positioning mattering doesn't always feel good, though, especially when it comes to the creep enemies and the Arkham Militia story asset, meant to represent the waves of smaller creatures that constantly rush into each other in MOBA games. There's a single Arkham Militia that can move around the map, dealing damage to enemies in its area, and needs to have its uses recharged by spending clues. They're meant to fight low health, high swarming enemies - which means when they're not around, those enemies are a major threat that needs to be danced around, as they can deal 4 damage. This isn't as big of a problem during the beginning of the scenario, where there's more room to choose how to make engagements, but as the scenario progresses, there's less room to manuever the Militia while trying to use them for their other uses. The creep enemies deal so much damage - and often spawn on locations that can't be easily entered - that fighting them without the Militia ends up being a headache. And when the map expands, it might take too long to reposition the Militia to where they need to be. The Militia also can trivialize the boss enemies - while many of them have interesting mechanics, they have low enough health that they can just be wiped out by the Militia instead of engaging with them as printed, which is a real shame.
The location dance ends up highlighting the biggest issue with the scenario, which is the action economy. A set number of actions is required to make each tower vulnerable for attack - and in lower player counts, this just leads to turns where nothing happens. This is made worse by encounter cards that can keep you from moving or take away actions. Normally, said encounter cards are fine, especially in scenarios where positioning matters. But if a clue focused character wants to spend their next turn just moving, and their turn after that taking three actions (and no tests!) to open up the next location to go to. There's just too much of this, especially made worse by smaller player counts, where more of the scenario feels like waiting and positioning than actually doing things and having fun.
Defense of the Arkham has a different difficulty scaling compared to most standalone scenarios. At 19 XP, you don't get any further random basic weaknesses, but three encounter cards do change out for worse ones - they're not very worse, however, so it's a minor change. You need to increase your XP to 30-39 to get the additional random basic weakness common at 10-19 XP, allowing you to go in at 29 XP with no penalties besides the encounter card swap. I ended up playing it was 29 XP, only to find the scenario quite difficult - the high damage from enemies and the many demanding effects can be quite punishing. While there are some cards that can help make the scenario much easier, they're not common enough to expect them to be in any party.
Overall, Defense of the Arkham is a difficult scenario that suffers from trying to emulate its source material too closely. It's an interesting challenge, but one that can occasionally feel frustrating or dull from repetetive turns where nothing happens, or random encounter cards that can quickly throw plans out of whack.
Rewards
Scenario Cost: 3 XP
Potential XP Gain: 4 (locations) +1 (Hearld of the Immortal) +3 (tower guardians) +1 (Infernal Siege Machine, on Agenda 3 flip) +1 (N'oxthul)
In addition, there are five story assets that can be earned if found through the scenario:
