Fire Wall (Diablo I)

Fire Wall (a.k.a. Wall of Fire) is a spell in Diablo I.

General Information
Fire Wall summons a wall of flame that exists for a period of time. During this time, any being foolish enough to enter the flames will suffer Fire damage. The higher the level of the character, the higher the damage, and the higher the spell level, the longer the wall will last. Multiple firewalls do stack in effectiveness. Length of the wall does not change with levels.

It does deal damage to the character, if they enter it, which limits its effectiveness: one has to carefully position themselves and the enemy to keep the foes in the wall (most enemies do not attempt to escape the wall except for to chase the character). Most monsters will not advance into the flames, but this AI can be used against them: casting a Fire Wall in front of them, and then casting one on top of them, will make enemies stand and roast, since they're not smart enough to move backwards out of the fire. This is a very popular way to kill himself.

The spell can prove useful for a first time encounter with the first "boss" of the game, the Butcher. The reason for this is that as the player is usually at a low level, even with the expansion installed, even the toughest of heroes will have a hard time successfully surviving the Butcher's relentless and powerful attacks.

As multiple Firewalls can be stacked on top of each other, increasing the damage proportionally, this spell is very useful against monsters stuck on the other side of an obstacle.

The central sprite of the firewall (the casting point) does double damage. If Firewall damages the player who casts it, this damage is treated as a Trap (thus "of thieves" item will halve it) and is not blockable. Each space in the flame hits every .05 second for the duration. Damage Calculation:
 * Min. Damage: 4 + 2 x Character Level
 * Max. Damage: 40 + 2 x Character Level
 * Real Damage per tick: (Random[1-10] + Random[1-10] + Character Level + 2)/8
 * Duration: 8 + 8 x Spell Level seconds (12 + 8 x Spell Level in Hellfire)
 * Number of flames: 11 (6th is at the cast point, deals double damage)

Lore
''Magical fire feeds upon no earthly source, being fueled instead by the mystic energies known as Mana. While the heat of conjured flames may cause normal matter to combust and burn on its own, the flames themselves will burn as long they have Mana to draw upon. By carefully controlling the flow of Mana to a magical fire, its life-span can be extended well beyond that of a Firebolt or an Inferno. The Horadrim were skilled enough to create torches that burn with an eternal flame, but those abilities have been long lost. With this spell, the caster creates a wall of eldritch flame that will burn until the Mana in that area has been exhausted. As knowledge of this spell increases, the rate at which Mana must be consumed can be better controlled and the Wall of Fire can be made to burn longer.''