MyBB Tooltips
This section illustrates the 2 minutes step by step procedure for adding Magic the Gathering card tooltips to your mybb forum. If the images do not correspond to your setup, you might have a different mybb version installed than mine. Send me an email, and we'll work it out.
Including the javascript files
First, log in and visit the Templates & Styles tab in your Administration Control Panel. From the left menu, select Templates, and click on the Edit link of the default Header template.
In the textarea that will open add, just like the highlighted bit in the image, the following snippet. Then save the template.
<script src="https://deckbox.org/assets/external/tooltip.js"></script>
<script src="https://deckbox.org/assets/external/decks.js"></script>
Now it's time to insert a bit of javascript that will magically turn our deck tags into nice listings with card links and tooltips. Select the template footer (from the default templates listing where header was) and scroll down to the end and insert the following code (as shown in the following screenshot):
<script>Deckbox.utils.DeckParser.initializeMybb();</script>
That's it, you're done! All posts containing [mtg] tags around card names and decklists will turn these into nice links that show tooltips when you hover over them!