For me, in-person RPG, my favorite had to be when our DM at the time wanted us to create any PC from any Realm/setting, and to keep the specifics from all the other players.
The group of players wanted a campaign with more suspense, more treachery, more espionage.
So I created my PC to be a Lawful Evil Illrigger of Orcus.
The setting the DM had planned was in Greyhawk, and each player was given a different (yet similar) experience in how we all got to Greyhawk. We had our own backgrounds and objectives, etc.
To the group, I was a Paladin not of St.Cuthbert, but a Paladin none the less. One that never showed one’s (un)holy symbol, nor mentioned whom they worshipped to the group.
And yet I became the mentor to an actual Knight of St.Cuthbert.
As the player had never RP’d a Knight before, in-game getting mentored by another Holy-Warrior was a natural fit.
To be able to role play in what was a mostly “GOOD” group of PCs, and yet being the most “EVIL” among them, and them never knowing it. My “goals” were parallel and complemented the groups, up until near the end.
My PC personally saved the Knight on numerous occasions, and the group as well.
Part of my background was that Iuz had asked for some aid/advice was Orcus, and I was sent.
Iuz and St.Cuthbert were at war with each other, and once are group got together, we were sent to investigate increased raids by Orcs and Goblins from territories in league with Iuz, and to report back ASAP.
During one of our encounters, we had found the leader of these raids, a high-priestess of Iuz. Well, while the other PCs were fighting for their lives, I along with the Knight went for the leader. We were able to get close enough to her that we were able to speak to each other above the noise of the fighting. With me being in front to the Knight (being more senior). And without the Knight noticing what I was doing, I was able to show my (un)holy symbol to her before hiding it away once more. She looked from me to the knight of St.Cuthbert. Shock and amazement.
The knight moved forward, sword in hand, ready to end the life of the high-priestess.
My PC turned to the knight saying “Are you going to attack and kill an unarmed woman? Are you not going to ask for her to surrender into your care? Is that the type of knight you want to be known as? A butcher of defenseless ladies?”
The expression on the high priestess changed after that. She was now a pawn in an even bigger game. A game she was not ready to be a player in.
I then stated out loud “Will you surrender into (I pointed to the Knight) his custody!”
The player of the Knight was shocked I had made this declaration. I was role playing my character after all, and that my Paladin would offer this to the Knight was taken by the PC as a show of respect and part of his training/responsibilities, then the Knight too proclaimed, “Lady, will you surrender into my custody. I will protect you till I can deliver you to my superiors.”
When the knight ask her to surrender herself into his care and the knight swore to protect the high priestess with his life, until he could deliver her to be tried by his elders did she say yes.
The players and their PCs rejoiced and congratulated the Knight. I think the player was a little embarrassed at first, but was enjoying being a Knight now.
While on our way back to the capital, our group was ambushed and the Knight wanted to go after the strongest creature/leader attaching us, as a Knight should do. My Paladin told the Knight his first responsibility was to protect and guard the captive under his custody. The other PCs were once again fighting all over the place, and my Paladin moved to help the group by going after the leader, leaving the Knight to protect the high-priestess.
My leaving gave the ambushers enough time to try and rescue the high-priestess. My Paladin came back in-time to witness the fall of the Knight, and was able to dispatch the rest. My Paladin then faced the high-priestess. I came right up to her, and in a low voice only she could hear, “I am full filling my vow.” I cut her lose. “Next time, organize your troupes from the shadows. Let them think it is some random raiding. Have one clan raid, report their success, and have then next clan to do better than the previous one. Controlling the clans by working on their egos and dislike of one another, instead of trying to make them into one big army, until the very end. Let them think it is just the random raid and not you preparing for a big war/invasion.”
And with that, my Paladin turned to help the rest of the group finish the ambushers. As she was not my prisoner, as I had planned, I had no reason to keep her.
She quickly disappeared while the group finished the last of the ambushers.
The group wanted to go after her, but I stated, “We had got what we came for, no? We stopped the raids. And looking at all of us, are we in any shape to pursue? Besides, are we not told to report as soon as possible what we found?”
The group could not argue with that.
As one whom my PC was mentoring, my Paladin had decided to return the body of the fallen Knight.
When word spread that the raids were over, and the high-priestess was defeated, the country rejoiced.
Then word that a Knight of St.Cuthbert had died and was being returned home by a fellow holy-warrior, a Paladin the Knight was a friend to. The streets of the capital was lined up to see the sight.
When we came to the temple of St.Cuthbert, the clerics were all there. My Paladin stated, “I have returned the valiant body of your fallen Knight.”
They retrieved the body of their fallen Knight, and moved towards the entrance of the temple. My Paladin just stood there. The other players wonder what I was doing. The main cleric then asked my PC, “Sir, thanks for bringing back our Knight. Do come and…”
My Paladin put his hand up. “As we have come straight from the field, with Goblin and Orc blood and our sweat all over us, I will not offended your diety, nor you and your followers with their stench.”
The players thought this was just another one of my great Paladin role playing. Which was true, it also hid the truth.
And it was the other players who suggested to the main cleric (and the DM) to “make my Paladin an official friend of the order of St.Cuthbert with all the honours and privileges.”
The main cleric then took me to the side of the temple, to where the clerics live and eat and sleep. Here I was given a room to clean up and where I could come and go as I pleased.
The other players were all high fiving each other. They did not think they would get all this accomplished in the game.
But then they being mislead.
The player who had played the Knight, after the session was over, never thought playing a knight could be so fun, and challenging at the same time.
He asked if he could look at my character sheet. I looked at the DM, as in this group character sheets were off-limits to other players.
I said I have no problem with it, so long as nothing within is revealed to the other players.
So the DM said yes.
That player got to ready not only my stats, but all of my character’s history, background, motivations, allegiance too, etc.
The player was in shock.
My character was the anti-character they were all looking for. The treachery and espionage they expected to come from a NPC, not from a fellow PC.
I, along with the DM, had fooled everyone.
If my PC had stepped foot into the temple of St.Cuthbert, all the wards would go off. The evil on my (un)holy symbol, the fact my allegiance was in direct opposite to theirs, etc. would all come out.
And the players gave my Lawful Evil Illrigger full assess to the heart of the country, unlimited assess to the secret places to the temple.
When the true war came, my Paladin was there to show the high-priestess where to go.
You might ask, would not a Knight be able to detect the presence of evil? If they have no reason to, and my PC never gave them any reason to doubt my PC, they cannot and would not need to do so. Same went with the clerics. Give them no reason to think you are evil, and they will not treat you as such.
Of course, my PC did alot more doing this campaign, both with the Knight and afterwards, but this gives you the idea.
It was so much fun, and so memorable.