This trophy is gained by getting to rank 3 in the Alliance War, and thus unlock the title 'Recruit'.
To level up your rank in the Alliance War you can kill enemies, capture keeps, defend keeps, capture Elder Scrolls, and complete notice board quests in Cyrodiil.
Note: I suggest you have a mount before going to Cyrodiil otherwise you have a very long walk ahead of you. I also suggest you have some ability to heal (e.g. Dragonblood for Dragonknight), and are prepared to roll. Also, take a ranged weapon, it will help a lot
To enter the alliance war you must be at least level 10. Go to your menu in game (press start), and choose the 'campaign' tab. This will then show all of the available campaigns. It doesn't matter which one you join for this (although being with your guild/friends is better to make this achievement faster). Once you have joined a campaign you can change it once before you incur cost.
Now you are in your campaign enter it. There may be a queue to join which could take anywhere from a few minutes to a couple of hours. This is because there can only be a set maximum number of people in each alliance in the campaign at once. If you do wait then it will give you a pop-up when you can join, so just join the queue and continue with PvE for a bit.
Once in the campaign you will be in Cyrodiil at one of your two alliance's main bases (e.g. Eastern Elsweyr Gate), where you should begin by activating the wayshrines (for future convenience). Then, go and follow the tutorial quest, making sure you pick up the quests from the notice boards and purchase a siege weapon (I prefer trebuchet for better range).
Now you are prepared to venture into Cyrodiil. I will assume you are solo. Note that your stats (health, magicka, stamina, ability costs, armour rating and damage) are normalised so that no one has a major advantage on these. However, higher level people will have invested more skill points and therefore will likely be stronger based on better abilities and passives.
Cyrodiil is enormous (seriously) so plan your destination. Go to your map and look for either one of your keeps that is under attack or one of an enemy's that is under attack by your alliance. If you are dominion you are yellow, if you are pact then you are red, if you are covenant then you are blue. A keep shows up on the map as under attack if it has a spiky background in the colour of the attacking alliance. You can also check for battle by looking for two (sometimes three) crossed swords which are coloured to the fighting alliance. Use the transistus shrine to travel to the closest keep available to your destination, then get on your mount and ride there.
Some hints:
- Once you get to the battle you want to stick with the group of people in your alliance (being singled out will usually get you killed) and just keep killing everyone you see. In time you should be successful in attacking or defending by doing this.
-Be careful to check your surroundings. Your allies may die or run away which will leave you alone and very much dead.
- Never attack anyone if it means being outnumbered (even by one person) because you will probably die.
- Use your ranged weapon to hit enemies if you think you can't reach them before they die. This means that it counts as a kill for you, even though you didn't really kill them.
- Overall, staying alive will save you a lot of time because it saves you running back to the battle from the keep again.
- If you are struggling because the enemy is currently extremely powerful then just come back after a few hours (their best players may have gone offline or you best have come on).
Once you reach rank 3 the trophy should pop.