Arch-Viles are lean humanoid demons. They first appeared in Doom II, but also appear in Final Doom, and Doom 3. It does not appear in the original version of Doom. It was not included in the PlayStation version combining both games, due to the additional memory requirements necessary to load the large number of animation frames of the Arch-Vile. They have the fourth-highest number of HP (700). Their only attack consists of blasting their enemies. It first raises its arms up, which causes non-damaging fire to raise around the targeted foe. The Arch-Vile then hunches over and clamps its hands together, releasing a blast which causes the target considerable damage, with some splash damage, and can send it flying into the air. This attack will always hit the target instantly, so long as there is a line of sight between the Arch-Vile and the target when the attack is finished. The attack can be avoided by either hiding behind an obstacle before the attack is finished, or by causing the Arch-Vile to flinch by damaging it, though it is very resistant to pain. The Arch-Vile will use this attack to engage in monster infighting with other monsters who accidentally hit it. It would be difficult to have an Arch-Vile initiate infighting as its attacks are specifically targetted (i.e. no line of fire) so splash damage at the player (or another monster it is currently attacking) would be the only method. In Doom II and Final Doom, Arch-Viles are the fastest monsters, and encountering two of them at once can be quite challenging to some players. The Arch-Vile also has the unique ability to resurrect other monsters. They can revive all monsters except Cyberdemons, Spider Masterminds, Lost Souls and Pain Elementals (since they leave no body), and other Arch-Viles. This power makes the Arch-Vile a priority to kill in battle, so that they do not keep reviving monsters and forcing the player to waste precious ammo. On occasion, in user-made maps, Arch-Viles may be hidden within pillars or inside secret areas where they are close enough to revive monsters but are otherwise difficult to reach themselves. Its unique abilities are exploitable and can cause some bugs. Killing a resurrected monster will count towards the "Kill" percentage at the end of a level, making it possible to get more than 100% kills. It can be used to obtain some extra ammo, although it is somewhat risky. If there are a few zombies in the area, the Arch-Vile may revive them, and every time they are killed again, they will drop ammunition. Its fire attack can be exploited to do an Arch-Vile Jump and bypass some elements of a level and reduce game time. If an Arch-Vile resurrects a monster that was crushed to death, it can produce a ghost monster which is only vulnerable to splash damage from a rocket or barrel explosion and can move through some walls. However, this glitch has been fixed in several source ports for Doom.