Lego Harry Potter's
gameplay is similar to that of most previous Lego video games, with an
emphasis on collecting, exploring, and solving puzzles. Casting spells
is an integral part of the gameplay, with a wide range of spells
available for unlocking as the player progresses. As there are many
spells available in the game, the player can use the spell wheel to
select the spell. Potion-making is another integral feature; potions can
help the player complete levels or, if created incorrectly, have
adverse side effects such as turning the player into a frog.[6]
Changes
to the mechanics of previous games 'Student in Peril' missions, which
are a group of challenges to help a student, and Polyjuice Potion, which
allows players to temporarily change one of the player's characters
into any other mini-figure.[7] A
major change is to the hub system. Diagon Alley serves as a hub for
purchasing unlockable extras, The Leaky Cauldron works as a hub for
returning to previous levels, while Hogwarts acts as a constantly
evolving massive hub with the unlockable characters found by picking up
their hidden portraitsB