Invoker/Old

The name Old Invoker refers to the initial version of Invoker that existed from the time the hero was created in 6.10 until he was removed in 6.18. The two versions of Invoker share surface-level similarities, in that they both utilize three reagents to produce a spell when combined using the hero's ultimate. However, for Old Invoker, the order in which his reagents were summoned is also used to determine which spell is invoked, giving him access to a full 27 spells compared to the current Invoker's 10. For example, for Old Invoker,   and    would correspond with the spells Portal and Betrayal, respectively, whereas for the current Invoker, both would correspond with Ghost Walk.

Old Invoker was inspired by a Warcraft 3 map called "Spellcraft". At the urging of the mapmaker Bug, who was involved with Dota's development at the time, Guinsoo created Old Invoker with the intent to release the hero with patch 6.0. It is rumored that the daunting scope of the hero, however, bogged down development and in this sense was a contributing factor to Guinsoo's departure. It was not until patch 6.10, when IceFrog was the lead developer, that Old Invoker would finally be released to the public, initially as a Radiant hero before being switched to Dire. After several patches and balance changes, Old Invoker was removed from Dota in patch 6.18 for a number of reasons, most notably due to his unwieldiness, engine-related bugs, and difficulty to balance.

Those interested in playing Old Invoker in Dota 2 can do so in the custom game Retro Dota.

Trivia

 * One of Rubick's voice lines implies that Invoker used to be known as the rubick_ally_01.mp3 "Arsenal Magus", which may be a reference to Old Invoker.

Version history
6.18
 * Removed Invoker.

6.13
 * Fixed Shroud of Flames damaging buildings.

6.12
 * Quas icon.png Quas, Wex icon.png Wex and Exort icon.png Exort no longer have a 25 mana cost.
 * Reduced Invoke icon.png Invoke cooldown from 15 to 12.
 * Shroud of Flames Now applies a magical damage barrier with 50/100/150/200/250/300/350/400 health, instead of 4%/8%/12%/16%/20%/24%/28%/32% magic resistance.

6.11
 * Reduced base attack damage from 16-23 to 3-19 (total attack damage is now 25-41).
 * Reduced Exort icon.png Exort health regeneration per level per instance from 0.5 to 0.3.
 * Invoke icon.png Invoke no longer refreshes cooldowns of currently active spells when re-invoking them.
 * Reduced Energy Ball radius from 400 to 300.
 * Reduced Chaos Meteor radius from unknown to unknown.
 * Fixed various Betrayal bugs.

6.10
 * Created.