Don't Forget to Bring a Gasmask! 
The Noxious Fumes ruleset is one of my favorites to see pop up. For those not familiar with the name, you may know it as every monster starts with poison. This ruleset is one of my favorites because it allows for a multitude of different strategies and tends to favor those who try to strategize, rather than brute force wins with leveled up cards.
From my experience, here are a few hopefully viable tips to consider that may aid you in battle when this particle ruleset pops up. We will cover two main topics: Important Abilities to know and the importance of ordering your monsters correctly.
Please keep in mind my experience is limited to Gold League and below, I’m sure the meta shifts dramatically as more monsters unlock abilities.
Important Abilities to Known
While it is important to know most, if not all, abilities available to your monsters, there are a select few that stand out and deserve to be mentioned specifically for Noxious Fumes. This is not an exhaustive list, just some of the most common and important abilities you will encounter.
The first being “Immunity”. The ability makes the monster immune to all negative status effects, and this includes poison. If you utilize a monster with this ability, such as Almo Cambio, you can potentially stall your opponent out and allow the poison to do all the work. Few cards have this ability, less than 10, so it’s pretty easy to recognize those that do. It is important to know that armor nor divine shield protect from poison, it will occur unless the monster has immunity.
The second ability is “Cleanse”. This ability removes any negative status effects on your front line monster. Noxious fumes only apply poison at the beginning of the battle, not at the top of each round. So, it only takes one cleanse to get rid of poison for the rest of the match, unless reapplied by an enemy monster. This ability typically appears on low hp monsters that die earlier in the battle, but that is alright as their job gets done if they go once. It also should be known that Scared Llama Mage will cleanse your front line monster every turn.
The third ability to know is “ Scavenger”. This ability causes the user to gain 1 HP every time a monster dies, ally or enemy. And, as we all know, lots of monsters die due to the poison. With this ability it is key to remember the importance of monster ordering as it will make a difference. One RNG factor that you can’t control is who’s team gets hit with poison first, you almost always want to be the second one hit to allow your scavengers the chance to buff up as they typically have low starting health. Gelatinous Cube is an excellent example of a card that excels in this ruleset, mainly due to this ability.
The final ability is probably the most powerful, “Heal”. The heal ability allows many monsters to neutralize the poison damage each turn, some manage to outheal it entirely. By placing a monster with heal in the middle of your team they can often serve as a last resort when your frontline falls, or a stall out mechanic. It is not uncommon to see a Noxious Fumes battle end with Almo Cambio facing someone with heal, and the healer generally wins.
Monster Ordering
The ordering of your monster is always key to victory, but when Noxious Fumes occur you may want to alter your normal habits. As previously stated, one team will always take damage before the other and this will often be a deciding factor in who wins. Monsters are hit in order from Front line to back, each taking 2 damage at the end of the round.
If using a scavenger it is generally best to have them towards the back, but not the backline. You don’t want them tanking all the monster damage and dying too soon. Oftentimes it is wise to throw in some low hp monsters that you know will die in order to allow the scavenger to survive, if it survives the first wave of poison you’re looking good.
Don’t be afraid to throw in low HP monsters just because they die after one round, that is all they need in many cases and their death will not be in vain if you have a scavenger. Some eaxmples of this are Halfling Alchemist and Herbalist, both die quick but do their job.
If using a card with immunity such as Almo, I prefer to place him near the center of the team. As long as the opponent doesn't have a self-healer, very few cards will outlive Almo due to the poison.
If possible I would advise throwing in a monster with Affliction, just in case your opponent uses someone with heal. Their placement isn’t super important, as long as they can get an attack off. But, do remember affliction is not always applied on a hit.
Another viable strategy is to place a monster with taunt near the back as they tend to be high health and are able to absorb both the poison damage and monster attacks. This should take some stress off your frontline and allow them to survive a little longer.
You should always look at your opponents history and plan accordingly, as frequently you can make an educated guess on what they will try.
Wrapping Up
The Noxious Fumes ruleset often serves as an equalizer of sorts, not to be confused with the ruleset of the same name. While I am not certain, I strongly believe that my winrate in matches with the ruleset is substantially higher than those without. Whether the mana cap is high or low, if you plan ahead the victory is almost always attainable.
