A leitmotif is a musical phrase or melody that is re-used in different songs to associate a song with a person, place, or event. Used right, leitmotifs can evoke feelings from previous scenes or hint at a character's relationships and role in the world, getting the game designer free characterization without ever saying a word. Plus, using leitmotifs means the musician doesn't have to design as many melodies!
Undertale[]
Undertale uses many musical leitmotifs to great effect. Consider the track ASGORE.
Undertale Ost- 077 - ASGORE
ASGORE has four leitmotifs present. Bergentrückung, or Asgore's theme starts the track off, intimidating the player with a much more intense mix of the track they just heard. However, the main leitmotif in ASGORE is from Heartbreak, or the music that players when the player fights Toriel. This establishes Asgore's link to Toriel, and shows that he is still deeply hurt by losing her. It also uses leitmotifs from Determination, the music for the game over screen, and Undyne's theme.
The Vanishing of Ethan Carter[]
The Vanishing of Ethan Carter - Welcome to Red Creek Valley Trailer
Leitmotifs are absolutely compelling, and the most memorable experience I've had with them recently is in The Vanishing of Ethan Carter. The environments in this game captivated me, so I spent hours sifting through practically every square foot of the accessible environment and getting different visual perspectives on landmarks and widely captivating detail that went into the game. While sauntering through the game, I noticed when the player enters a new area, the music composition transitions perfectly into another melody that aims to create a certain feeling in the player. I played around with these "trigger boxes" where the transitions happen, and it's so awesome how the game's soundtrack flows into different moods between areas. Even though many studios have recognized how important a game soundtrack can be, I still find them to be underrated even though they have the ability to make or break the mood of a game, or even elevate a good game to a great game. Leifmotifs are at the core of changing the player's feeling and emotion, and I agree that tailoring melodies to certain characters, events, and places in games can make them more memorable and compelling for the player.
- JimmyEatWorld91
Elder Scrolls V: Skyrim[]
Skyrim does a great job with incorporating leifmotifs into the game. When you go underground into a dungeon then the music changes to match the aesthetic around you. This makes the dungeon seem ten times creepier than being outside in the sunlight. The music is just absolutely beautiful in this game! Another example of leitmotif is how the music will change when an enemy is nearby. It gives you that extra time to prepare which is really helpful with game play. It also gives you that "oh no" kind of sensation because something is going to happen!
Left 4 Dead 2[]
In L4D2, leitmotifs are actually a crucial indicator during gameplay. Each type of special "infected" has a leitmotif, which will play when one is nearby or has spawned. Once players learn to distinguish these leitmotifs from each other, they can efficiently prepare to fight a certain kind of infected. This is balanced because it doesn't provide non-infected players with an exact location of the new special infected, but simply makes the non-infected aware. Each campaign in L4D2 has its own soundtrack and set of leitmotifs (based on the game's theme song) which add a unique aesthetic vibe to each.
For more examples of leitmotifs in games, visit TV Tropes