Arsonist

Mechanics

 * If you do not choose an action at night you will clean yourself. This only matters if there is at least one more Arsonist.
 * You will not be ignited even if you are doused again this night.
 * If you choose a target (dousing or igniting), then change your mind to do nothing, you will not clean yourself and can be ignited.
 * You will win a stalemate versus Godfather, Serial Killer and Jailor (if they have no executions left).
 * A jailed target can be saved from being doused or ignited.
 * Anyone who is revived by a Retributionist will lose their doused status, regardless of how they died.
 * Dead players that were doused but not killed by you can still technically be ignited. This can be helpful in obtaining the "Disco Inferno" Achievement (Igniting 5 players in one night) since they don't still have to be alive for you to ignite them.
 * A Veteran will be doused even if on alert. This only matters if there are at least two Arsonists in the game or if you get saved by a Doctor.
 * If a Bodyguard protects your target when you are dousing, you will kill each other. They will not, however, kill you when you ignite, regardless of whether they're protecting one of your targets or you yourself.
 * Every Arsonist can ignite targets that have been doused by other Arsonists. This makes it possible to ignite a target each night including the first night.
 * To ignite each night, the Arsonist who is dousing must select his target before another Arsonist selects to ignite.
 * Despite the wording of their goal, Arsonists do not always have to live to the end of the game to win; if there are multiple Arsonists in a game, you will win as long as any one of them is victorious.

Strategies
As an Arsonist, you are the number one target/threat for the Mafia, Town, Serial Killers and Werewolves. This is because you are a strong powerful role which can get away with almost anything. So stay undetected as much as possible.

Who to douse

 * Your ideal situation is to reach the end of the game with as many people as possible doused. Therefore, your goal is to figure out who is likely to live until the end of the game, and douse those people, avoiding the ones who are likely to die by other means.  Somebody just revealed himself as the Sheriff? Chances are this player will be dead the following day without you intervening.
 * Dousing quiet people has a lot of advantages. They're often evil roles (who tend to live longer); they're less likely to attract the attention of other killers or Bodyguards; and, perhaps most importantly, they're a bit less likely to speak up and announce that they were doused.  The longer you can avoid having someone publicly announce they were doused, the better for you.
 * You don't need to douse absolutely everyone. The Arsonist wins in all one vs one situations except against the Werewolf, the Jailor (if they have executions left), the Mayor (they can hang you with their voting power), or the Veteran (if they have alerts left).  Eliminating all these roles is essential for victory, though you may want to delay on some of them and hope that they're eliminated by someone else (especially, of course, the Veteran.)
 * You don't need to douse and ignite in large chunks. Depending on the roles then it is normally a viable strategy to only douse 2 or three people then ignite. This removes the ability to say that you were doused but it allows you to kill people fast and arouse suspicion for everyone. If you know who certain investigative roles are then you should douse and ignite them first to gain some breathing room after your first and possibly second ignition.
 * In particular, while you need the Mayor dead to win, you may want to avoid dousing them yourself in the hope that someone else will kill him for you. Not only is he likely to be protected by Bodyguards and Lookouts, dousing the Mayor also ensures that he'll focus his attention on finding you, and also usually along with the rest of the town, which is better avoided.
 * The Survivor and the Witch can win together with you. Likewise, dousing a Jester is pointless because they're trying to die anyway (and because their goals coincide with yours, provided you don't vote Guilty on them); dousing an Executioner is pointless because their goal doesn't conflict with yours.  If you're certain you've identified any of these roles, don't bother dousing them.  Avoiding dousing Witches in particular is important because they can prevent you from igniting if they identify you.
 * However, remember that evil roles often claim Survivor or pretend to be a Jester or Executioner.  The last thing you want is to ignite, only to find that you're alone with a Werewolf who kills you the next night, or that the Jester and Survivor you spared are actually Mafia members who proceed to lynch you.  Additionally, remember that Survivors, Jesters, Executioners, and Witches might vote unpredictably; if you ignite with one Mafia or Town left and a survivor or neutral evil, you run the risk of the swing vote turning against you and lynching you.
 * The Arsonist role can be a big threat. Sometimes Survivors, Amnesiacs, etc. might purposely lynch you even if they know you are Arsonist, manly because 1) an Amnesiac or pretend Amnesiac wants to become an Arsonist, or 2) you will attack through night-immunity and this is a problem for roles such as Executioner and Amnesiac. (Which might want to remember being an immune role.)
 * Sometimes, it can be advantageous to skip dousing anyone and use the night to claim doused yourself in order to deflect attention. Remember that after you've done this, you cannot ignite unless it would win you the game immediately, since your failure to burn to death would put you under immediate suspicion; additionally, be cautious about skipping douses, since you're trading a concrete advantage for a gambit that may or may not convince anyone.
 * On the bright side of doing this, you may need to un-douse yourself, making the perfect excuse. Also, this is a Jester tactic-claim you are doused and when Arsonist ignites and town sees that you are still alive, you might get lynched or accused of being a Jester.
 * Avoid dousing famous or controversial names. They will often have Bodyguards or Lookouts on them, which will result in your death.  Additionally, they're more likely to be killed by someone else.
 * It's important to track who is doused to avoid messing up at your game-finishing ignite. (A great way of doing this is keeping everything on your will or death note.)

When to ignite

 * Ideally, you only want to ignite when it would win you the game; this means leaving you with only one other person alive, at most. Igniting before that both causes you to waste a chance to douse, and drastically reduces the number of people who could be the Arsonist, making you easier to find.  Depending on who's left, they might even identify you instantly.
 * Another disadvantage to igniting too early is that it exposes wills. An Investigator who discovers that you're Arsonist / Transporter, for instance, might just write that in his will and wait on revealing it to avoid becoming a target for the Mafia; since Town wills provide confirmed evidence, it's to your advantage to avoid making them appear.
 * If you are doused, do not ignite or douse the next night. Instead, stay idle and don't attack and you will (If you aren't jailed or role blocked or controlled) receive the message "You have cleaned the gasoline off your body." This means that you are no longer doused and same from another Arsonist igniting.
 * It can occasionally be worth igniting early if you have a number of dangerous threats doused (such as the entire Mafia, the Serial Killer, Bodyguards, the Werewolf, and so on.) Try to figure out who will be left after your ignition, and determine if they'll be able to catch you before you can douse and ignite the remaining targets; weigh the risk of getting killed by the threats you've already doused vs. the risk of getting caught by the people you haven't doused yet.

Threats

 * Even though you have Night Immunity, night killers like the Serial Killer, Mafioso, and Godfather are still the greatest threat to you. Most of the time, all it takes is one hit from one and a death note outing you to get you lynched.  If you do get hit, you need to have a strategy to deal with the accusation; note that there is no strategy that works reliably.
 * You can claim you were transported, but most of the time the town will expect a Transporter to come forward to confirm this.
 * You can claim Survivor (or imply that you're an Executioner), but this is unlikely to save you after you've been accused; it's better used as an early claim to avoid getting attacked in the first place.
 * You can claim you were healed by a Doctor (doctors are less likely to reveal than Transporters, and the Town won't expect it.) Be warned that a Doctor's healing does not produce the immunity message, so your attacker will know you're lying; however, unless they're a Vigilante, they can hardly say so publicly.
 * You can claim you're a Bodyguard, but since they only have one vest (and therefore the chance of it getting hit is low, especially if you haven't been publicly revealed as a Bodyguard earlier), this rarely works.
 * You can simply say that your accuser is lying, especially if it's a death note from an evil role. However, the town will usually accepts accusations of immunity in a Death Note, especially if people have been announcing they were doused.
 * Roleblockers like Escorts, Consorts, and the Jailor can prevent you from igniting, even if they only find you very late in the game. It can sometimes be worth an early ignite to kill them.  If you doused a Witch, then they're your enemy along the same lines.
 * The Jailor can also, of course, execute you. It's important to have a claim ready for if you're jailed; note that as usual, your Investigative result of Transporter is usually a poor claim - even if the Jailor can't consult with the rest of the Town while you're jailed, you'll likely be executed if your fake will says you transported them.  Roles with easier-to-fake wills like Sheriff, Escort, Bodyguard, Vigilante, Medium, and Doctor are better claims, though the latter few are hazardous due to being common claims by evil roles.
 * The Consigliere is a major threat, since they can identify you flawlessly, alert the Town in a Death Note, and instruct Consorts to roleblock you.
 * The Investigator is a similarly dangerous threat; your Investigation results are Arsonist / Transporter, and it's very hard to convincingly pretend to be a Transporter (since the Town will expect to be able to confirm your will.) You can claim to have been transported, but this rarely works (the Town will expect the Transporter to step forward in your defense.)
 * Bodyguards are extremely serious threats; since you need to douse most of the town, a bodyguard who simply covers the same person every night will almost certainly kill you. Taking down a Bodyguard is one of the few reasons you might consider igniting early; however, remember that if a Bodyguard is confirmed, then they're likely to be killed by one of the game's other killers.
 * The Werewolf can ignore your night immunity and, like the Bodyguard, can catch you by targeting people who haven't yet been doused. Of course, if you know who the werewolf is, you can often just get them lynched instead of dousing them.
 * The Vampires are a threat because they can both identify you by failing to convert you, and can identify you by process of elimination if they take over much of the Town. They're one of the reasons it's a bad idea to ignite early, since even if you thought the undoused targets were harmless Doctors and Sheriffs, you might find yourself surrounded by Vampires who will immediately deduce your identity.
 * Lookouts can only identify you if their target reveals that they were doused; this is another reason why it's a good idea to douse quiet people.
 * Transporters are dangerous because they can make it hard for you to figure out who was doused, especially if people are silent about it; you won't get any indication that your target was swapped, which can lead to you dousing the same person twice and ending up with one more person alive after your ignite than you counted on. Additionally, a Transporter can keep you from igniting (and can sometimes make you ignite early by accident.)
 * The Mayor can kill you one-on-one, and can force you to claim a role; but since they're also a major target for the Mafia (and will often prioritize them over you, especially if they haven't personally been doused), they're often not your first concern. Additionally, one advantage to having a confirmed Mayor is that they very likely tie up the Bodyguard, if there is one, making it safer for you to douse everyone else.
 * A Retributionist can screw up your calculations by reviving someone on the night you ignite. Additionally, note that currently, anyone a Retributionist revives is cleaned of dousing (regardless of the way they died.)  This may be a bug.
 * The Veteran is an obvious threat in that they can kill you if you try to douse them; worse, your usual strategy of waiting for the Mafia to kill them for you might not work here, since the Mafia is going to want to save confirmed Veterans for last, too (and that means they're probably going to hit you first.) And worst of all, you don't automatically win 1v1 against a Veteran, so you need to eliminate them somehow.  Your best options are to wait and hope someone else takes a potshot at them despite the risk; or to eventually douse them near the end and hope they wasted their alerts.  Be particularly cautious if the Town is announcing every single douse; this means that if you save the Veteran for the last douse you need before igniting, they might figure it out and alert that night.
 * The Spy, Sheriff, Vigilante, Doctor, Vampire Hunter, and Medium are mostly not threats to you. The Spy can confirm themselves to narrow down the suspect list, the Medium can bring back logic and information from the dead, and a Vigilante can discover your immunity with a potshot, but these are not normally major threats compared to the above.  If you're reasonably certain that everyone you haven't doused is one of these roles (plus unaffiliated neutrals), then it might be worth igniting early.

What to Claim

 * One option is to claim Survivor, which explains your Night Immunity; this is more likely to get you lynched if people are getting doused, so if you take this route, you may want to avoid dousing anyone early on... but declining to douse has its own risks, since you'll have to douse quickly near the end of the game and hope that no other faction gets an overwhelming majority. If you do claim Survivor, it's important to do it early, before you get attacked; claiming it after you're accused of being immune will almost certainly get you lynched, since the Town has no real reason to keep a Survivor alive.
 * Another option is to imply that you're an Executioner; accuse someone at random, and (assuming they're Town) thank the Town after they're lynched. You can even just thank the Town after a random lynch of any innocent Town member.  This will both divert attention and explain your night immunity.  However, it carries several risks; you may be executed by a Jailor or lynched by a vengeful Town, and Investigators and Consiglieres can still identify you.  Also, if you delay on dousing to reinforce your disguise, you may find the Town turning their suspicion back to you, with no real way of ending things quickly.
 * It is rarely practical to claim Transporter, even though your Investigation results are Transporter / Arsonist. This is because the Transporter produces two messages for their targeted Town members every time they act, which makes it easy for them to prove their role, and very hard for you to claim it; if you claim Transporter, the Town will demand a will, and you won't be able to provide one without it being immediately called out as false.
 * If you're going to claim a Town role, almost anything you can fake a will for will work; since your Investigative result of Transporter is generally not viable, you should avoid claiming a specific Town role unless absolutely forced to (or unless you're certain there's no Investigators around to contradict you.)

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