Medals

Medals are the main method of earning Experience. There are four tiers of each medal, with each tier giving more experience. At the end of the game, you're awarded an xp bonus depending if your team won or lost the game. The winning xp bonus is 750xp/medal and the loosing xp bonus is 250xp.
 * Tier1 Medal = 200
 * Tier2 Medal = 400
 * Tier3 Medal = 700
 * Tier4 Medal = 1250

The actions that award medals are described below. Be aware that some of these medals are at the moment nearly impossible to achive in certain game modes such as the "slayer" in team deathmatch.

Damage ("Devastator")

Tier 1: 2000 damage, Tier 2: 8000 damage, Tier 3: 22000 damage, Tier 4: 35000 damage

Healing ("Savior")

Tier 1: 1000 healing, Tier 2: 5000 healing, Tier 3: 12000 healing, Tier 4: 20000 healing

Protection ("Protector")

Tier 1: 1000 protection, Tier 2: 2500 protection, Tier 3: 5000 protection, Tier 4: 15000 protection

Kills ("Slayer")

Tier 1: 5 kills, Tier 2: 10 kills, Tier 3: 25 kills, Tier 4: 35 kills

KillStreak ("Cold Blooded")

Tier 1: 3 kills without dying, Tier 2: 5 kills without dying, Tier 3: 7 kills without dying, Tier 4: 9 kills without dying

Assists ("Ally")

Tier 1: 15 assists, Tier 2: 25 assists, Tier 3: 40 assists, Tier 4: 60 assists

AssistStreak ("Cohort")

Tier 1: 5 assists without dying, Tier 2: 7 assists without dying, Tier 3: 9 assists without dying, Tier 4: 12 assists without dying

Captures ("Treasure Hunter")

Tier 1: 3 relic points captured, Tier 2: 5 relic points captured, Tier 3: 7 relic points captured, Tier 4: 9 relic points captured

Defenses ("Defender")

Tier 1: 5 kills of a relic carrier, Tier 2: 12 kills of a relic carrier, Tier 3: 20 kills of a relic carrier, Tier 4: 32 kills of a relic carrier

Survivor ("Survivor")

Tier 1: survive for 240s (4:00), Tier 2: survive for 420s (7:00), Tier 3: survive for 600s (10:00), Tier 4: survive for 890s (14:50)

Towers ("Siegebreaker")

Tier 1: tug on towers for 60s (1:00), Tier 2: tug on towers for 120s (2:00), Tier 3: tug on towers for 200s (3:20), Tier 4: tug on towers for 300s (5:00)

Credit for description of medals goes to KingJackaL (original post #13)