ACKS II: System Compatibility Guide

I love these conversion guides that come with games, and ACKS II includes a great one.

"If you are arriving here by way of D&D Fifth Edition or Pathfinder, then this book may seem a strange and surreal tome, alien and perhaps even old-fashioned. As an OSR product, it emulates the design ethos of the golden age of role-playing games from 1974 – 1983." - ACKS II System Compatibility Guide, page 1.

ACKS II is an OSR game, and like any of the games, such as Labyrinth Lord, Old School Essentials, Swords & Wizardry, AD&D, ADAD, Castles & Crusades, or the ...Without Number games - they all play so well together.

One aspect of ACKS II that I love is that it flips the whole descending versus ascending AC argument on its head. The game uses descending AC, where an AC of 0 is excellent, and gives characters a target number to hit, such as a 14+ on a d20. Then, AC is simply added to the attack throw. A higher AC is easier to hit, such as an AC 7 target, which is a +7 to the roll.

ACKS II also clarified the language using a throw versus a check, which makes the game far easier to grasp and play.

"The throw mechanic puts the emphasis on the character, rather than the situation. A player understands that if he has “Listening 14+” in most circumstances his character can eavesdrop on a roll of 14-20. If there is a modifier to this chance, it’s transparent to the player: “A penalty of -4 to your roll due to the loud noise”. 

In contrast, systems such as 5E or Pathfinder, which use a fixed bonus against a variable difficulty, put the emphasis on the Judge’s decision as to the situation. In some games, the Judge is actually encouraged to calculate what chance he wants for success, and to then ‘customize’ the Difficulty accordingly (this is explicit in D&D 4E). 

These sort of accounting illusions are unnecessary in ACKS. Where we believed a task should be equally challenging for characters of varying level, we simply use a type of throw that doesn’t change with level (such as the proficiency throw to bash open doors)." 

- ACKS II System Compatibility Guide, page 1.

That explanation tells you all you need to know about ACKS II. The game isn't "grading on a curve" when it comes to high-level characters, and arbitrarily making all the locks in this castle DC 25 because there happens to be a higher-level adventure going on in here at the moment. Or else they would be too easy! Right? We can't have that.

I love how this example calls out D&D 4E for "massaging" the chance to succeed and "faking it" - well done. That game was so full of tricks and deceptions to make you feel more powerful than you actually were, such as the fireball spell, which was only valid as a "minion mop." That game was one of the largest shell games played in the hobby's history of D&D. In D&D 5E, they hid things a little better, but a lot did not change, especially getting weaker as you leveled, and fights still took forever.

A "Listening 14+" throw tells me precisely what my character can do, and gives me the odds right there. If the referee wishes to make it easier or more complicated, that is their decision.

That solid design ethos is baked into ACKS II, and the system will not let you down.

This game is not particularly challenging. The core concepts are the same as those of Old School Essentials and other games. To get started with ACKS II, begin by using the conversion guide and applying your existing OSR knowledge.