Here are several ways to tell legal Classic pieces from illegal 2021+ pieces.

1. Copyright. Every HeroClix set has the release year date written into the copyright. If it's 2002-2020, it's legal. If it's 2021 or newer, it's illegal. The only exception to this is the final 2017 set, Fantastic Four: Future Foundation, which was released in early 2021 and didn't reflect the impending system changes.

2. Promo codes. For promo pieces, the figure's code will always reference the year of release. For example, with Thor #MVP25-005, the 25 means it was released in 2025. Likewise, Gwenpool #MP18-004 and Power Woman #DP18-007 means they were released in 2018.

3. Visually. 2021+ figures stand on big colored slabs.

4. HC Manager (Android only). Use the 2017 filter when searching. Be wary of bugs, though.

5. Suspicious use of Indomitable. If a figure has the striped shield symbol and you feel like it probably shouldn't, then you might want to double check it. This isn't always the best way to tell but can be helpful.