In Dungeons & Dragons, cantrips are often among the most fun spells a caster is capable of. Since they have an unlimited number of uses, players can feel free to experiment with them in a way that isn't possible when trying to conserve spell slots and components. This means cantrips that allow for a high level of creativity are the most useful and fun to have.
While straight combat spells like Eldritch Blast or Fire Bolt understandably get a lot of attention for being damage-dealing and uncomplicated, there are plenty of others that are incredibly useful outside of combat. Shape Water is one of these. Though the spell is easy to overlook, it may even be one of the best cantrip options in the game.
Shape of Water offers a variety of applications that seem simple enough. Casters can move and animate water, color it and even freeze it. The spell's wording makes its combat-applications difficult, but even without combat applications, it can come in handy with just a little bit of creative thinking.
One of Shape Water's most common applications is freezing water into ice. By doing this, players can bypass most mundane locks by moving water into the locking mechanism and freezing to break it. With one simple trick, a party with access to Shape Water no longer needs a Rogue's lockpicking skills, offering instead a more reliable option.
Beyond that, the spell is invaluable when around large bodies of water. It can create a platform of ice to stand on when there may be a risk of drowning, move water out of the way when searching for objects or do the opposite to create a hiding spot. However, so long as the Dungeon Master permits it, Shape Water really come alive when casters explore how it can be used in combat.
Creative players can use Shape Water to freeze the ground (making it difficult terrain), lay a trap of ice spikes, distribute ice spears for anyone who does not have a weapon or plant enormous ice boulders in precarious positions where they can fall atop a target. Many high-level spells will be preferable in the midst of combat, but when it comes preparing ahead of time, Shape Water can use the battlefield into the party's advantage.
Sometimes, a spell's limitations can actually be used to a player's benefit, and players can use Shape Water's inability to freeze around creatures to test chests and other objects to make sure they're not Mimics. Overall, there are no limits to what a creative player can do with a cantrip like Shape Water. This spell is incredibly versatile, and whether players are in combat, on the road or just sitting at a tavern, they will find a use for Shape Water -- making it just as useful as any Eldritch Blast.