The "unblocked" version is usually a stripped-down Flash or HTML remake, so don't expect AAA graphics. But for 10 minutes of fun between classes? Absolutely worth it.
Sites like sometimes host old Flash or HTML5 games, including Gladiator II versions. These are often not flagged as "gaming" by filters. gladiator ii unblocked
Searching for "gladiator ii unblocked" is a rite of passage for students who love strategy and history. Just remember: The "unblocked" version is usually a stripped-down Flash