Arbiter

Arbiter could refer to:

The rank of Arbiter is given to an elite officer who has disobeyed a higher covenant official in the arbiter in halo 2's case, disobeying a prophet. The rank is only used when a suicide mission is necessary, it gives the elite one last chance to be honorable and die honorably
 * The Arbiter Rank, a Covenant rank used only when a suicide attack is necessary.
 * The Arbiter Character, the former Supreme Commander of the Fleet of Particular Justice and later a leader of the Covenant Separatist movement.
 * The Arbiter, the sixth campaign level in Halo 2.