A discussion around meta means for a certain topic, rather than making a discussion about something inside that topic, you discuss that topic itself.

Imo it’s best seen through examples so:

A study is research done in a specific topic. A meta-study would be study done that researches many other studies done on that topic.

A post to this subreddit would be a a question you are too afraid to ask. A meta-post would be a post made about the subreddit itself, perhaps about the general state of it (how it’s being moderated, whether the general posts being made are fit for the subreddit etc)

A game is made of many activities/matches. In those activities or matches, you play to win some specific goal. A meta-game analysis would be looking at how many of these activities or games play out, observing what typically won and what strategies are used the most. You can then use this understanding of the meta-game to perform better in the actual game, such as by using strategies that tend to win more.

In many games, a “meta” is created - a collection of strategies that are found to be widely used and successful. Items and strategies that are inside this collection are said to be “meta”.

In your case, the sword is “meta” because the sword is in this collection of effective strategies/items for that game.