Required
Omen Threat Meter
What Omen does is provide accurate values of your group's relative threat level on individual enemies, so that you can see when you're in danger of pulling aggro (or, if you're next on the snack list if your tank bites it). This info is usually critical in raids, where only tanks can survive aggro, but it's useful for any multi-player situation.
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oRA2 MT Targets
oRA2 is a lightweight CTRA replacement. Its features include Main Tank target frames feature which displays all the raid's designated tanks and their current target as click-targetable bars.
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Deadly Boss Mods
Deadly Boss Mods is a boss alert mod. It consists of many individual "boss modules", mini addons that are designed to trigger alert messages and event timer bars for one specific raid boss each.
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BigWigs Boss Mods
BigWigs is a boss alert mod. BigWigs aims to be as efficient as possible (creating a lower memory per second footprint and using a lower amount of CPU than any other boss mod), as effectively as possible. When modules are written every aspect of the encounter is revised. Is syncing required? Is target scanning required? What events are really to be warned for.
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Decursive
This is a cleaning mod. Its job is to help a class that can remove afflictions to do it with ease in every conditions (playing solo, in small groups or in big raids). All applicable classes are required to run this or an equivalent setup that allows for quick removal of debuffs.
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AVR
AVR (Augmented Virtual Reality) allows you to draw and add lines, circles and other markings on the 3D world itself. All markings may also be shared with others. Suitable for example to mark locations when explaining raid tactics. These marks can even be left visible for the fight itself. This also serves as a framework for other addons to draw markers for various other purposes.
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AVR Encounters
AVR Encounters (AVRE) is a boss mod agnostic add-on that integrates with AVR to provide visual effects in 3D that highlight various boss mechanics. There currently are modules for ICC and Ulduar being developed and refined.
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Highly Recommended
Recount
Recount is a graphical combat statistics (e.g. damage) meter.
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Clique
Clique is a simple GUI that lets you assign click-casting for any number of unit frames. Click casting allows you to define the behavior the game takes when you click on a frame. This can be casting spells, running a macro, using an item, or something as simple as changing targets or assisting a unit.
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Optional
OmniCC
OmniCC is an addon that adds text to items/spells/abilities that are on cooldown to indicate when they'll be ready for use. OmniCC should be compatible with any addon that uses a cooldown model.
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AtlasLoot Enhanced
AtlasLoot Enhanced is an UI mod allowing for loot tables of bosses to be browsed whenever needed within the game. It can access full item tooltips, show drop rates, allow items to be chat linked and to use the dressing room.
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Grid Raid Frames
Grid is a modular, lightweight and screen-estate saving grid of party/raid unit frames written by Pastamancer and Maia. Optional modules can be assigned to up to 7 possible indicators: each corner, a border center text and center icon - to highlight specific units (and if you prefer to only show units in range, this is posible too). Grid comes with a bunch of modules (aggro indicator, incoming heals, auras (debuff types, shield, renew, rejuv, mortal strike,...), mana, health deficit,...), but it's easy to add your own modules (see the developer API).
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Necessary Addons for Raiding:
Healbot
Healbot is a Raid Frames alternative for healers, allowing the assignment of key mouse combinations to cast beneficial spells (heals or affliction removal) to custom raid unit frames, and the monitoring of buffs / debuffs.
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X-Perl Unit Frames
Perl, with Extra stuff. Much enhanced from Nymbia's Perl UnitFrames, and a complete replacement for Blizzard's default unit frames, including raid frames and raid tools, with little remaining of the original Nymbia code.
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