In King Lear, Shakespeare plays with the idea of 'nothing'. The King asks his daughter to profess her love, and she says that she cannot because her love is not the kind that easily becomes words - she says 'nothing' instead. The King replies that 'nothing shall come of nothing', and it is his lack of understanding for the value of the inexpressible that brings his downfall.
For viewers of King Lear, the 'play' is both the activity on the stage and the interpretation of the words to form a coherent interpretation of the lines that are spoken. This form of play, using story interpretation as a mechanic of gameplay, is currently underused in video games, and a strong area for exploration.
In our writing for games, we are tempted to put everything onto the page, with all motivations clearly and explicitly stated for the player to understand. The teams we work with may worry that players won't be able to follow stories with nuance or implied meanings, but to push our medium further we need to work with ambiguity in the lives of our characters and allow players to fill in the absences. Where sentences trail off, lines are interrupted, or silence used, the player will naturally search for meaning in our words (or lack thereof). We can use these traits in our writing to take it beyond being dressing for traditional gameplay activities and towards making the full comprehension of the relationships between the characters part of the game's appeal.
In complement to the concept of leaving words unsaid, games have huge potential to expand notions of unreliable narrators. This writing technique has been used with great success in many famous works of literature, from the framing devices of 'Frankenstein' and 'Wuthering Heights', to the delusional Patrick Batemen in 'American Psycho'. There are two forms of this that can be of use to us: characters who see themselves differently from how the player is expected to see them, and characters whose reality we see but don't trust.