This paper proposes a game to study strategic communication on platforms by parties. Parties’ platforms have been chosen in a multidimensional policy space, but are imperfectly known by voters. Parties strategically decide the emphasis they put on the various issues, and thus the precision of the information they convey to voters on their position on each issue. The questions we address are the following: what are the equilibria of this communication game? How many issues will they address? Will parties talk about the same issues or not? Will they talk on issues that they "own" or not?