diff --git a/conftest.py b/conftest.py
new file mode 100644
index 0000000..e69de29
diff --git a/guild/migrations/0015_alter_character_name_alter_npc_name.py b/guild/migrations/0015_alter_character_name_alter_npc_name.py
new file mode 100644
index 0000000..7a1bf57
--- /dev/null
+++ b/guild/migrations/0015_alter_character_name_alter_npc_name.py
@@ -0,0 +1,22 @@
+# Generated by Django 4.2.1 on 2023-08-25 20:42
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("guild", "0014_alter_playsession_npcs"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="character",
+            name="name",
+            field=models.CharField(max_length=255, unique=True),
+        ),
+        migrations.AlterField(
+            model_name="npc",
+            name="name",
+            field=models.CharField(max_length=255, unique=True),
+        ),
+    ]
diff --git a/guild/models.py b/guild/models.py
index 10fc08a..18aefb9 100644
--- a/guild/models.py
+++ b/guild/models.py
@@ -77,7 +77,7 @@ class Character(models.Model):
         RETIRED = "RETIRED", _("Retired")
         UNKNOWN = "UNKNOWN", _("Unknown")
 
-    name = models.CharField(max_length=255)
+    name = models.CharField(max_length=255, unique=True)
     description = models.TextField()
     status = models.CharField(
         max_length=16, choices=Status.choices, default=Status.ALIVE
@@ -106,6 +106,10 @@ class Character(models.Model):
     def __str__(self):
         return self.name
 
+    @classmethod
+    def get_by_name(cls, name):
+        return cls.objects.filter(name=name).get()
+
     def get_absolute_url(self):
         return reverse("guild:character_detail", kwargs={"pk": self.pk})
 
@@ -203,7 +207,7 @@ class Reward(models.Model):
 
 
 class NPC(models.Model):
-    name = models.CharField(max_length=255)
+    name = models.CharField(max_length=255, unique=True)
     description = models.TextField()
 
     picture = models.ImageField(
@@ -222,3 +226,7 @@ class NPC(models.Model):
 
     def get_absolute_url(self):
         return reverse("guild:npc_detail", kwargs={"pk": self.pk})
+
+    @classmethod
+    def get_by_name(cls, name):
+        return cls.objects.filter(name=name).get()
diff --git a/guild/templatetags/guild_extras.py b/guild/templatetags/guild_extras.py
index 19d926a..bf2bb75 100644
--- a/guild/templatetags/guild_extras.py
+++ b/guild/templatetags/guild_extras.py
@@ -1,6 +1,7 @@
 import markdown
 from django import template
 from django.template.defaultfilters import stringfilter
+from guild_md.entity_links import GuildLinkExtension
 
 register = template.Library()
 
@@ -8,4 +9,4 @@ register = template.Library()
 @register.filter(name="md")
 @stringfilter
 def md(value):
-    return markdown.markdown(value)
+    return markdown.markdown(value, extensions=[GuildLinkExtension()])
diff --git a/guild_md/__init__.py b/guild_md/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/guild_md/entity_links.py b/guild_md/entity_links.py
new file mode 100644
index 0000000..6617f2a
--- /dev/null
+++ b/guild_md/entity_links.py
@@ -0,0 +1,68 @@
+"""
+Guild Journal Extension for Python-Markdown
+======================================
+
+Converts [[NPC/Frankie]] to links.
+
+Original code Copyright [Waylan Limberg](http://achinghead.com/).
+
+All changes Copyright The Python Markdown Project
+
+License: [BSD](https://opensource.org/licenses/bsd-license.php)
+
+"""
+
+from markdown.extensions import Extension
+from markdown.inlinepatterns import InlineProcessor
+from guild.models import NPC, Character
+import xml.etree.ElementTree as etree
+
+
+def build_url(category: str, name):
+    """Build a URL from the label, a base, and an end."""
+    if category.lower() == "char":
+        try:
+            return Character.get_by_name(name).get_absolute_url()
+        except Character.DoesNotExist:
+            return ""
+    elif category.lower() == "npc":
+        try:
+            return NPC.get_by_name(name).get_absolute_url()
+        except NPC.DoesNotExist:
+            return ""
+    return ""
+
+
+class GuildLinkExtension(Extension):
+    def extendMarkdown(self, md):
+        self.md = md
+
+        # append to end of inline patterns
+        GUILD_RE = r"\[\[([\w0-9_ -]+)\/([\w0-9_ -]+)\]\]"
+        wikilinkPattern = GuildLinksInlineProcessor(GUILD_RE, self.getConfigs())
+        wikilinkPattern.md = md
+        md.inlinePatterns.register(wikilinkPattern, "guildlinks", 75)
+
+
+class GuildLinksInlineProcessor(InlineProcessor):
+    def __init__(self, pattern, config):
+        super().__init__(pattern)
+        self.config = config
+
+    def handleMatch(self, m, data):
+        if m.group(1).strip() and m.group(2).strip():
+            category = m.group(1).strip()
+            name = m.group(2).strip()
+            url = build_url(category, name)
+            a = etree.Element("a")
+            a.text = name
+            a.set("href", url)
+            if url == "":
+                a.set("class", "invalid-url")
+        else:
+            a = ""
+        return a, m.start(0), m.end(0)
+
+
+def makeExtension(**kwargs):  # pragma: no cover
+    return GuildLinkExtension(**kwargs)
diff --git a/pytest.ini b/pytest.ini
new file mode 100644
index 0000000..15e297f
--- /dev/null
+++ b/pytest.ini
@@ -0,0 +1,4 @@
+
+[pytest]
+DJANGO_SETTINGS_MODULE = guild_journal.settings
+python_files = tests.py test_*.py *_tests.py
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/test_markdown_extension.py b/tests/test_markdown_extension.py
new file mode 100644
index 0000000..ac9ffed
--- /dev/null
+++ b/tests/test_markdown_extension.py
@@ -0,0 +1,48 @@
+import pytest
+import markdown
+from guild_md.entity_links import GuildLinkExtension
+from guild.models import NPC, Character
+
+
+@pytest.mark.parametrize(
+    ["objs", "md", "html"],
+    [
+        [
+            [],
+            "",
+            "",
+        ],
+        [
+            [Character(name="Blimm")],
+            "[[Char/Blimm]]",
+            '<p><a href="/characters/1/">Blimm</a></p>',
+        ],
+        [
+            [Character(name="Blimm")],
+            "[[Char/Lun]]",
+            '<p><a class="invalid-url" href="">Lun</a></p>',
+        ],
+        [
+            [Character(name="Blimm"), Character(name="Lun")],
+            "[[Char/Lun]] and [[Char/Blimm]]",
+            '<p><a href="/characters/2/">Lun</a> and <a href="/characters/1/">Blimm</a></p>',
+        ],
+        [
+            [NPC(name="Frank")],
+            "[[NPC/Frank]]",
+            '<p><a href="/npcs/1/">Frank</a></p>',
+        ],
+        [
+            [NPC(name="Frank"), Character(name="Blimm")],
+            "[[Char/Blimm]] and [[NPC/Frank]]",
+            '<p><a href="/characters/1/">Blimm</a> and <a href="/npcs/1/">Frank</a></p>',
+        ],
+    ],
+)
+@pytest.mark.django_db
+def test_link_conversion(objs, md, html):
+    for obj in objs:
+        obj.save()
+
+    output = markdown.markdown(md, extensions=[GuildLinkExtension()])
+    assert output == html