Blackman uses the symbols of noughts and crosses to distinguish between the two groups warring for power within her novel. A reference to the British version of tic-tac-toe, noughts and crosses is a game composed of two sides represented by a circle for the noughts and an X for the crosses. She associates noughts with the color white and crosses with the color black. The color and shape of each symbol contribute to its meaning throughout the novel.

The lighter skinned noughts face discrimination in the Cross-dominated society Blackman describes. The word nought means nothing and represents the lack of value attributed to them by the darker-skinned Crosses. Callum explains that “even the word was negative. Nothing. Nil. Zero. Nonentities” (84). Blackman furthers this discrimination by creating the derogatory term of blanker, a term which enrages Callum. The symbol of the cross carries a religious connotation as the shape of an X resembles that of the Christian cross. Blackman chooses this meaning to emphasize the religious justification for discrimination promoted by the Crosses who believe they are favored by God to rule over noughts. Blackman uses the term dagger as the derogatory term for Crosses to convey the danger and treachery associated with Crosses by the nought community.