diff --git a/evennia/commands/cmdhandler.py b/evennia/commands/cmdhandler.py
index aaa4bcdd85..02a31720e4 100644
--- a/evennia/commands/cmdhandler.py
+++ b/evennia/commands/cmdhandler.py
@@ -250,7 +250,9 @@ def _progressive_cmd_run(cmd, generator, response=None):
         if isinstance(value, (int, float)):
             utils.delay(value, _progressive_cmd_run, cmd, generator)
         elif isinstance(value, str):
-            _GET_INPUT(cmd.caller, value, _process_input, cmd=cmd, generator=generator)
+            _GET_INPUT(
+                cmd.caller, value, _process_input, session=cmd.session, cmd=cmd, generator=generator
+            )
         else:
             raise ValueError("unknown type for a yielded value in command: {}".format(type(value)))
 
@@ -698,7 +700,10 @@ def cmdhandler(
                 # Parse the input string and match to available cmdset.
                 # This also checks for permissions, so all commands in match
                 # are commands the caller is allowed to call.
-                matches = yield _COMMAND_PARSER(raw_string, cmdset, caller)
+                try:
+                    matches = yield _COMMAND_PARSER(raw_string, cmdset, caller, session=session)
+                except TypeError:
+                    matches = yield _COMMAND_PARSER(raw_string, cmdset, caller)
 
                 # Deal with matches
 
diff --git a/evennia/commands/cmdparser.py b/evennia/commands/cmdparser.py
index 11d8e067be..0c321a7b12 100644
--- a/evennia/commands/cmdparser.py
+++ b/evennia/commands/cmdparser.py
@@ -111,7 +111,7 @@ def try_num_differentiators(raw_string):
         return None, None
 
 
-def cmdparser(raw_string, cmdset, caller, match_index=None):
+def cmdparser(raw_string, cmdset, caller, match_index=None, session=None, **kwargs):
     """
     This function is called by the cmdhandler once it has
     gathered and merged all valid cmdsets valid for this particular parsing.
@@ -166,7 +166,7 @@ def cmdparser(raw_string, cmdset, caller, match_index=None):
         matches = build_matches(raw_string, cmdset, include_prefixes=False)
 
     # only select command matches we are actually allowed to call.
-    matches = [match for match in matches if match[2].access(caller, "cmd")]
+    matches = [match for match in matches if match[2].access(caller, "cmd", session=session)]
 
     # try to bring the number of matches down to 1
     if len(matches) > 1:
diff --git a/evennia/commands/command.py b/evennia/commands/command.py
index 8931442bb4..c3bbe08b0a 100644
--- a/evennia/commands/command.py
+++ b/evennia/commands/command.py
@@ -16,7 +16,7 @@ from django.utils.text import slugify
 from evennia.locks.lockhandler import LockHandler
 from evennia.utils.ansi import ANSIString
 from evennia.utils.evtable import EvTable
-from evennia.utils.utils import fill, is_iter, lazy_property, make_iter
+from evennia.utils.utils import is_iter, lazy_property, make_iter
 
 CMD_IGNORE_PREFIXES = settings.CMD_IGNORE_PREFIXES
 _RE_CMD_LOCKFUNC_IN_LOCKSTRING = re.compile(r"(^|;|\s)cmd\:\w+", re.DOTALL)
@@ -383,7 +383,7 @@ class Command(metaclass=CommandMeta):
                     return k, v
         return None, None
 
-    def access(self, srcobj, access_type="cmd", default=False):
+    def access(self, srcobj, access_type="cmd", default=False, session=None):
         """
         This hook is called by the cmdhandler to determine if srcobj
         is allowed to execute this command. It should return a boolean
@@ -395,9 +395,10 @@ class Command(metaclass=CommandMeta):
             access_type (str, optional): The lock type to check.
             default (bool, optional): The fallback result if no lock
                 of matching `access_type` is found on this Command.
+            session (Session, optional): The session to pass to lock functions.
 
         """
-        return self.lockhandler.check(srcobj, access_type, default=default)
+        return self.lockhandler.check(srcobj, access_type, default=default, session=session)
 
     def msg(self, text=None, to_obj=None, from_obj=None, session=None, **kwargs):
         """
@@ -595,7 +596,7 @@ Command \"{cmdname}\" has no defined `func()` method. Available properties on th
                 "help-entry-detail",
                 kwargs={"category": slugify(self.help_category), "topic": slugify(self.key)},
             )
-        except Exception as e:
+        except Exception:
             return "#"
 
     def web_get_admin_url(self):
diff --git a/evennia/commands/default/help.py b/evennia/commands/default/help.py
index dbdfe65374..95ec0f3dc3 100644
--- a/evennia/commands/default/help.py
+++ b/evennia/commands/default/help.py
@@ -421,7 +421,9 @@ class CmdHelp(COMMAND_DEFAULT_CLASS):
         cmdset.make_unique(caller)
         # retrieve all available commands and database / file-help topics.
         # also check the 'cmd:' lock here
-        cmd_help_topics = [cmd for cmd in cmdset if cmd and cmd.access(caller, "cmd")]
+        cmd_help_topics = [
+            cmd for cmd in cmdset if cmd and cmd.access(caller, "cmd", session=self.session)
+        ]
         # get all file-based help entries, checking perms
         file_help_topics = {topic.key.lower().strip(): topic for topic in FILE_HELP_ENTRIES.all()}
         # get db-based help entries, checking perms
diff --git a/evennia/game_template/server/conf/cmdparser.py b/evennia/game_template/server/conf/cmdparser.py
index 831990a89d..cd3a727344 100644
--- a/evennia/game_template/server/conf/cmdparser.py
+++ b/evennia/game_template/server/conf/cmdparser.py
@@ -32,7 +32,7 @@ your settings file:
 """
 
 
-def cmdparser(raw_string, cmdset, caller, match_index=None):
+def cmdparser(raw_string, cmdset, caller, match_index=None, **kwargs):
     """
     This function is called by the cmdhandler once it has
     gathered and merged all valid cmdsets valid for this particular parsing.
diff --git a/evennia/locks/lockfuncs.py b/evennia/locks/lockfuncs.py
index 4121107b22..8f77bcb6f0 100644
--- a/evennia/locks/lockfuncs.py
+++ b/evennia/locks/lockfuncs.py
@@ -518,14 +518,13 @@ def is_ooc(accessing_obj, accessed_obj, *args, **kwargs):
     account = obj.account if utils.inherits_from(obj, evennia.DefaultObject) else obj
     if not account:
         return True
-    try:
-        session = accessed_obj.session
-    except AttributeError:
-        # note-this doesn't work well
-        # for high multisession mode. We may need
-        # to change to sessiondb to resolve this
-        sessions = session = account.sessions.get()
-        session = sessions[0] if sessions else None
+    session = kwargs.get("session", None)
+    if session is None:
+        try:
+            session = accessed_obj.session
+        except AttributeError:
+            sessions = account.sessions.get()
+            session = sessions[0] if sessions else None
     if not session:
         # this suggests we are not even logged in; treat as ooc.
         return True
diff --git a/evennia/locks/lockhandler.py b/evennia/locks/lockhandler.py
index eba0e64509..97da785294 100644
--- a/evennia/locks/lockhandler.py
+++ b/evennia/locks/lockhandler.py
@@ -363,7 +363,7 @@ class LockHandler:
             access_type, rhs = [part.strip() for part in lockdef.split(":", 1)]
             if not access_type:
                 err = _(
-                    "Lock: '{lockdef}' has no access_type " "(left-side of colon is empty)."
+                    "Lock: '{lockdef}' has no access_type (left-side of colon is empty)."
                 ).format(lockdef=lockdef)
                 if validate_only:
                     return False, err
@@ -514,13 +514,15 @@ class LockHandler:
 
         """
         old_lockstring = self.get(access_type)
-        if not lockstring.strip().lower() in old_lockstring.lower():
+        if lockstring.strip().lower() not in old_lockstring.lower():
             lockstring = "{old} {op} {new}".format(
                 old=old_lockstring, op=op, new=lockstring.strip()
             )
             self.add(lockstring)
 
-    def check(self, accessing_obj, access_type, default=False, no_superuser_bypass=False):
+    def check(
+        self, accessing_obj, access_type, default=False, no_superuser_bypass=False, session=None
+    ):
         """
         Checks a lock of the correct type by passing execution off to
         the lock function(s).
@@ -580,7 +582,16 @@ class LockHandler:
             evalstring, func_tup, raw_string = self.locks[access_type]
             # execute all lock funcs in the correct order, producing a tuple of True/False results.
             true_false = tuple(
-                bool(tup[0](accessing_obj, self.obj, *tup[1], access_type=access_type, **tup[2]))
+                bool(
+                    tup[0](
+                        accessing_obj,
+                        self.obj,
+                        *tup[1],
+                        access_type=access_type,
+                        session=session,
+                        **tup[2],
+                    )
+                )
                 for tup in func_tup
             )
             # the True/False tuple goes into evalstring, which combines them
diff --git a/evennia/locks/tests.py b/evennia/locks/tests.py
index ba3a509f6a..978ffcb903 100644
--- a/evennia/locks/tests.py
+++ b/evennia/locks/tests.py
@@ -7,13 +7,15 @@ the stability and integrity of the codebase during updates.
 This module tests the lock functionality of Evennia.
 
 """
+
+from evennia.server.serversession import ServerSession
 from evennia.utils.test_resources import BaseEvenniaTest
 
 try:
     # this is a special optimized Django version, only available in current Django devel
-    from django.utils.unittest import TestCase, override_settings
+    from django.utils.unittest import override_settings
 except ImportError:
-    from django.test import TestCase, override_settings
+    from django.test import override_settings
 
 from evennia import settings_default
 from evennia.locks import lockfuncs
@@ -220,6 +222,19 @@ class TestLockfuncs(BaseEvenniaTest):
         self.account.unpuppet_all()
         self.assertEqual(True, lockfuncs.is_ooc(self.account, self.char1))
 
+    def test_is_ooc__multi_session_mixed(self):
+        """Test that two sessions on the same account can have different IC/OOC states."""
+        ic_session = self.session
+
+        # Create a bare unpuppeted session. Full login flow steals the puppet from ic_session in
+        # MULTISESSION_MODE 0.
+        ooc_session = ServerSession()
+        ooc_session.sessid = 2
+        ooc_session.puppet = None
+
+        self.assertFalse(lockfuncs.is_ooc(self.account, self.char1, session=ic_session))
+        self.assertTrue(lockfuncs.is_ooc(self.account, self.char1, session=ooc_session))
+
 
 class TestPermissionCheck(BaseEvenniaTest):
     """