diff --git a/testing/web-platform/meta/dom/events/AddEventListenerOptions-passive.html.ini b/testing/web-platform/meta/dom/events/AddEventListenerOptions-passive.html.ini
new file mode 100644
index 0000000000000..fb160377e0c08
--- /dev/null
+++ b/testing/web-platform/meta/dom/events/AddEventListenerOptions-passive.html.ini
@@ -0,0 +1,28 @@
+[
+AddEventListenerOptions
+-
+passive
+.
+html
+]
+[
+returnValue
+should
+be
+ignored
+if
+-
+and
+-
+only
+-
+if
+the
+passive
+option
+is
+true
+]
+expected
+:
+FAIL
diff --git a/testing/web-platform/meta/dom/events/Event-constructors.html.ini b/testing/web-platform/meta/dom/events/Event-constructors.html.ini
new file mode 100644
index 0000000000000..e4c1118f3e468
--- /dev/null
+++ b/testing/web-platform/meta/dom/events/Event-constructors.html.ini
@@ -0,0 +1,23 @@
+[
+Event
+-
+constructors
+.
+html
+]
+[
+Event
+constructors
+2
+]
+expected
+:
+FAIL
+[
+Event
+constructors
+3
+]
+expected
+:
+FAIL
diff --git a/testing/web-platform/meta/dom/events/Event-defaultPrevented-after-dispatch.html.ini b/testing/web-platform/meta/dom/events/Event-defaultPrevented-after-dispatch.html.ini
new file mode 100644
index 0000000000000..6cc547a1bc008
--- /dev/null
+++ b/testing/web-platform/meta/dom/events/Event-defaultPrevented-after-dispatch.html.ini
@@ -0,0 +1,20 @@
+[
+Event
+-
+defaultPrevented
+-
+after
+-
+dispatch
+.
+html
+]
+[
+Default
+prevention
+via
+returnValue
+]
+expected
+:
+FAIL
diff --git a/testing/web-platform/meta/dom/events/Event-initEvent.html.ini b/testing/web-platform/meta/dom/events/Event-initEvent.html.ini
new file mode 100644
index 0000000000000..265471e534f7a
--- /dev/null
+++ b/testing/web-platform/meta/dom/events/Event-initEvent.html.ini
@@ -0,0 +1,59 @@
+[
+Event
+-
+initEvent
+.
+html
+]
+[
+Properties
+of
+initEvent
+(
+type
+true
+true
+)
+]
+expected
+:
+FAIL
+[
+Properties
+of
+initEvent
+(
+type
+true
+false
+)
+]
+expected
+:
+FAIL
+[
+Properties
+of
+initEvent
+(
+type
+false
+true
+)
+]
+expected
+:
+FAIL
+[
+Properties
+of
+initEvent
+(
+type
+false
+false
+)
+]
+expected
+:
+FAIL
diff --git a/testing/web-platform/meta/dom/events/Event-returnValue.html.ini b/testing/web-platform/meta/dom/events/Event-returnValue.html.ini
new file mode 100644
index 0000000000000..f5f05aec144b4
--- /dev/null
+++ b/testing/web-platform/meta/dom/events/Event-returnValue.html.ini
@@ -0,0 +1,103 @@
+[
+Event
+-
+returnValue
+.
+html
+]
+[
+When
+an
+event
+is
+created
+returnValue
+should
+be
+initialized
+to
+true
+.
+]
+expected
+:
+FAIL
+[
+preventDefault
+(
+)
+should
+not
+change
+returnValue
+if
+cancelable
+is
+false
+.
+]
+expected
+:
+FAIL
+[
+returnValue
+=
+false
+should
+have
+no
+effect
+if
+cancelable
+is
+false
+.
+]
+expected
+:
+FAIL
+[
+preventDefault
+(
+)
+should
+change
+returnValue
+if
+cancelable
+is
+true
+.
+]
+expected
+:
+FAIL
+[
+initEvent
+should
+unset
+returnValue
+.
+]
+expected
+:
+FAIL
+[
+returnValue
+=
+true
+should
+have
+no
+effect
+once
+the
+canceled
+flag
+was
+set
+.
+]
+expected
+:
+FAIL
diff --git a/testing/web-platform/meta/dom/events/EventTarget-dispatchEvent-returnvalue.html.ini b/testing/web-platform/meta/dom/events/EventTarget-dispatchEvent-returnvalue.html.ini
new file mode 100644
index 0000000000000..95a54176b0bab
--- /dev/null
+++ b/testing/web-platform/meta/dom/events/EventTarget-dispatchEvent-returnvalue.html.ini
@@ -0,0 +1,45 @@
+[
+EventTarget
+-
+dispatchEvent
+-
+returnvalue
+.
+html
+]
+[
+Return
+value
+of
+EventTarget
+.
+dispatchEvent
+(
+)
+affected
+by
+preventDefault
+(
+)
+.
+]
+expected
+:
+FAIL
+[
+Return
+value
+of
+EventTarget
+.
+dispatchEvent
+(
+)
+affected
+by
+returnValue
+.
+]
+expected
+:
+FAIL