Translate the old name without losing the change
An older Conquest Dark guide may call the stat Instant Attack Chance. The 0.21 notes explicitly rename it Rapid Attack Chance. Searching for the old label in a newer interface can therefore be confusing even when the underlying build concept is recognizable. The name change is confirmed, while a complete cross-version interface glossary is not provided in the source set.
The same patch changes part of the mechanic rather than only replacing text. Keep the rename and the balance adjustment together when updating a build. It would be inaccurate to say that every ability is unaffected just because the stat still exists. It would also be inaccurate to say that primary attacks receive the same reduction as other abilities.
The primary-attack exception is explicit
For Primary Attack Abilities, the patch says the stat remains unchanged. It contrasts them with other abilities and explains that primary attacks still have a casting animation that Rapid Attack does not affect. The announcement's comparison is about this difference in behavior. It does not establish that all primary attacks share identical animation times.
That distinction prevents a common overstatement about the word instant. A named stat does not by itself prove that the entire animation vanishes. The developer specifically refers to an animation that remains part of the action. Exact timing for each weapon set remains 待确认 without direct ability-level evidence.
Other abilities use the documented lower cooldown reduction
For all other abilities, the stated cooldown reduction changes from 95% to 50% in 0.21. If an old setup relied on rapidly repeating a non-primary effect, this change is relevant to its compatibility. Identify the affected ability before attempting to explain a slower result. A percentage from the patch is not a complete performance benchmark.
Do not convert the reduction into a single universal DPS-loss figure. The supplied notes do not provide all attack timings, proc interactions, target availability or other bonuses needed for that calculation. Damage may also be split across multiple sources in the same build. Any exact before-and-after build output remains 待确认 until it has a suitable test.
Put the Zir and Sigil history in the correct order
Version 0.20.7 says Sigil of Flames can use Zir, then described as the Instant Attack Chance rune. That older compatibility note helps explain why a pre-0.21 Sigil build might emphasize the stat. Later, 0.21 changes the stat behavior for non-primary abilities and adjusts Sigil of Flames itself. Those are separate changes that need to be read together.
The Sigil patch reduces its beam count from two to one and increases its stated damage value from 25% to 50%. It does not publish a controlled end-to-end comparison of the old and new build. Do not claim unchanged practical damage just by multiplying beam count and the two percentages. See the Sigil of Flames page for the narrower confirmed conclusions.
Check equipment instead of assuming the old stat source remains
A separate 0.19.5 change replaces the Stalker Set's exceptional Instant Attack Chance stat with Projectile Damage. An older list that relies on obtaining the old stat from that source can therefore be wrong even before the 0.21 rename. Equipment history and mechanic history answer different compatibility questions. Both can matter to the same copied setup.
Read the installed set tooltip, then identify which other sources the build requires. This page does not provide a complete current inventory of Rapid Attack sources or a verified universal cap. Those details remain 待确认. It records the changes supported by the retained announcements without constructing a fictional optimization table.
A practical review sequence
First identify whether the important ability is a Primary Attack Ability or another type. Then translate the old stat label, check whether the source item still grants it and compare the relevant patch rule. Keep the old setup's version attached to your notes. These are review steps, not a claim that this guide has tested the build on every ritual.
If an imported build accepts the old configuration, still inspect what Auto-Build actually chose. Other requirements may be unavailable or may have changed. Use the build compatibility guide for that wider check. The direct answer remains the same: the new name is Rapid Attack Chance, and the primary/non-primary distinction is essential.