I'll make a quick note here: things around and on your person can be used in a non-lethal manner, following the same path as a lethal attack. A touch of creativity is all it takes.
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The Assassin brought the chain to the forefront, wrapping it somewhat tightly around his right hand as he slowly approached the guard from behind. Dead bodies didn't take long to start reeking like no tomorrow, and he needed this guy to stay unnoticed until, at the very least, the boat arrived tomorrow.
So, he decided to go with a different tact...
Roll(1d20)+14: 19,+14 Total:33
Guard DC: 10
Roll(1d20)+14: 20,+14 Total:34 CRIT SUCCESS
The Assassin's moves were fluid and unstoppable. He quickly wrapped the length of the chain around the guard's neck, earning a surprised gasp from the soon-to-be-retired guard before clamping his right hand onto his mouth, the chain wrapped around it somewhat bruising the guard. Still, this allowed for a anchor for one half of the chain, allowing the Assassin to use his left hand to pull the chain tight around the guard's neck, a vice grip tightening all around the guard.
What gasps and groans might've come were muffled by chain and the Assassin's hand, the Assassin slowly watching as the color began to fade from the guard's face. With no air and no blood rushing to his head, the guard's struggling died down, until it seemed he lost consciousness.
Releasing his grip and the chain, the guard dropped down to the ground like a tree, laying flat on the ground as the Assassin bent down and removed his helmet.
"Good way to quickly knock someone out... but as soon as you get enough air and blood back in that noggin you'll be up in no time..." The Assassin stated, picking up the lock. "You know, at first I thought this lock was pretty much garbage..." A quick strike to the crown of the guard's head solicited a quick groan, a bruise immediately forming in the area the guard was struck.
"But its grown on me, just like that bruise is about to grow on you." The Assassin stated, laying the chain and lock to the side as he cracked his finger. "Now then, hope you don't mind if I take this... and this... and this..."
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Locking the cell door behind him, the Assassin hung the ring of keys back into their place on the armor's hip like he had seen the guard do earlier. Wearing the guard's helm, armor and sword, the Assassin looked into the room to see the guard, laid down in a corner facing away from the cell door, his prison garb now worn by him, his arms bound in the chain and lock as his had been.
"Right then, that went far more smoothly than I thought. Didn't even have to kill the guy." A quick crack of his knuckles punctuated this statement, as the Assassin began looking around the area. The armor would do well to disguise him, the helmet obscuring his face and hiding his hair, but he knew he wouldn't be safe for too long, and he had a time limit unless he wanted to spend another night on this island, risking further exposure.
Assassin Passive Perception= 16
The tall tower was all the way on the other side of the prison, this tall monolith obviously housing the self aggrandized warden he had been sent to snuff out.
Do we head straight through the compound in order to get to the tower, or should we pace ourselves.
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Items Updated
Lock Pick
Leather Armor (+2 AC, -0 DC)
Short Sword (+3 AP)
Ring of Keys