Prime Decanus

"The Prime Decanus lead Legionnaires into battle, typically in a squad leader role. They have better equipment and have displayed leadership and combat skill greater than their inferiors the Recruit Decanus. Their direct superiors are the Veteran Decanus and Centurion."

Starting out
You'll spawn in the legion camp with your gear. It's probably best you find a superior to get your objectives from. Head to the armoury and take a shortwave radio to communicate with your faction. You can use it without enabling the microphone with the chat prefix :l or :r depending on what hand the radio is in.

The Prime Decanus
To quote: https://fallout.fandom.com/wiki/Caesar%27s_Legion_military_hierarchy#Prime_legionary "Prime legionaries are better equipped than recruits. They also have the benefit of greater experience and training than the standard legionaries. In short, the prime legionaries are a full step above Caesar's recruits"

and:https://fallout.fandom.com/wiki/Caesar%27s_Legion_military_hierarchy#Legionary_decanus "Legionaries are given the position of decanus when they display leadership potential consistently in battle. A legionary decanus has the authority to run small camps as well as act as a deputy for the local centurion. Seniority determines the quality of the decanus' armor; a standard decanus will only have the recruit's armor whereas a seasoned decanus will be given a veteran legionary's armor. They are easily distinguished by their helmets, which are adorned with multiple feathers."

These two quotes should give you enough insight into your characters position within the legion, and your role. You should attempt to lead Legionnaires into battle, as a front line leader, allowing the Veterans to remain as a second wave, so that they can ensure objectives are completed.

You should be ensuring your ranks are disciplined, and fulfil the potential Caesar expects of them.

Chain of Command
Caesar. Legate. Praetorian. Centurion. Veteran Decanus. Decanus. Veteran Legionary/Explorer. Recruit Legionary/Scout. Camp Follower.

Legion specific rules
Vexillarius has no real rank. They hold a flag and doot doot. 0. No female or ghoul legionnaires.

1. Stay within the Roman theme of naming. You’d be given a new name when you join the Legion.

2. No medicine save for healing powder, poultice, bitter drink and mushrooms for anti-toxin. Chems must be disposed of.

3. The Legion uses any equipment it finds, but would not keep items like medical technology, or techno-magic items, such as bluespace backpacks.

4. Legion ranks are defined by equipment. Survivors traditionally reform the hierarchy by taking the armor of their dead superiors, to assume their position.

5. Caesar’s Legion consider women inferior, this delegates them to support and slavery, rarely if ever do they accept a woman as worthy as more than a slave.

6. NCR are typically strung up on a cross when captured (and if it is deem fitting, they can be turned into slaves),as are chem users.

7. Men are to be trained as Legionaries, while women are to be trained as healers and farmers, as well as cooks.

8. Caesar's Legion is comprised of mainly tribals, meaning most of them do not know how to read, however the Centurions of war camps are typically somewhat educated.

9. Camp Followers are entirely loyal to the Legion. Playing them as anything but is grounds for a jobban. There are reasonable exceptions to this, such as overt abuse by the Legion, who should at least treat you as an asset.