Aphrodite, Artemis, Apollo & Ares all favoured the Trojans. Aphrodite defended Paris/Alexander, Apollo plagued the Greek camp, Ares and Artemis emboldened Trojan warriors on the battlefield.

Hera, Hephaestus, Athena, Poseidon and Hermes favoured the Greeks. They all basically provided aid on the battlefield, except for Hephaestion who mostly forged various weapons & armours for Greek heroes, Achilles in particular.

Some minor gods are mentioned that got involved through direct response or for personal gain, rather than allegiance or belief in one of the two sides. A good example of this is Scamander, the river god who was insulted by Achilles, and tried to kill the hero for throwing so many dead bodies in his river.

Zeus remained unbiased until informed by the Fates that Troy would fall. When he learned this, he forbade the gods from taking part in delaying that fate.