Variable AC [Archive] - Wizards Community

Variable AC [Archive] - Wizards Community

Post/Author/DateTime Post
Orenmir
01-06-08, 11:15 PM Any DMs out there use a variable instead of the standard "10+" for Armor Class? I could envision using a d20 or d10+5 or 2d10 instead. It seems logical and maybe not even game breaking. The only downside I can see is that it adds more rolling and calculating to combat time -- making it arguably too drawn out.

If you do, let me know how it works for you. Do battles take longer? Do you let monsters, PCs, or NPCs take 10 on attack or AC rolls?

(thread (http://forums.gleemax.com/showthread.php?t=974518) that inspired this thread)
NoldorForce
01-07-08, 01:04 AM The primary difference is that it will increase whatever gap exists between attack modifiers and armor class modifiers. This is the general case for opposed-roll systems, that the person with the higher modifier has a much bigger chance of winning than the person with the lower modifier.

This happens because the high-modifier person has a chance of rolling so high as to shut out the low-modifier person. However, the nature of making opposed rolls is that the high-modifier person may roll terribly such that the low-modifier person has a chance of success when they wouldn't under a take-10 system (as normal with attacks vs. AC).
kuonji
01-07-08, 03:58 AM Any DMs out there use a variable instead of the standard "10+" for Armor Class? I could envision using a d20 or d10+5 or 2d10 instead. It seems logical and maybe not even game breaking. The only downside I can see is that it adds more rolling and calculating to combat time -- making it arguably too drawn out.

The first question I have is, what is your problem with AC? Do you simply not like the idea of a static AC or is it a problem with players/monsters ACs being too high or too low?

I wouldn't use random AC for the very reason you list, it adds more unnecessary dice rolling.

If you do, let me know how it works for you. Do battles take longer? Do you let monsters, PCs, or NPCs take 10 on attack or AC rolls?

(thread (http://forums.gleemax.com/showthread.php?t=974518) that inspired this thread)

I wouldn't use take 10 on any combat rolls. But I would like to point out that if you move the d20 roll to AC and use take 10 on the attack roll, it's pretty much exactly the same as using a d20 to make an attack roll and taking 10 on AC (since base AC starts at 10).
Orenmir
01-07-08, 05:28 PM The first question I have is, what is your problem with AC?

I don't have a problem with the RAW or the variable AC rule. I just like to explore the options. I'd like to hear DMs' opinions on how the variable AC (or opposed rolls) works for them. Just curious; not trolling.
Tequila_Sunrise
01-07-08, 07:31 PM Any DMs out there use a variable instead of the standard "10+" for Armor Class? I could envision using a d20 or d10+5 or 2d10 instead. It seems logical and maybe not even game breaking. The only downside I can see is that it adds more rolling and calculating to combat time -- making it arguably too drawn out.

This very variant was actually presented in Unearthed Arcana. I myself prefer less die rolls rather than more, so I've never used it. (I actually turn all opposed rolls, like grapple, etc., into single rolls opposed by DCs)

As to the game effect, well, more randomness nearly always works in the underdogs' favor. So big showdown fights with the BBEG will become a bit easier for the PCs, while mook fights will become a bit easier for the swarms of mooks.
JulesCARV
01-07-08, 07:33 PM I'd say that if you were to go with variable AC, you might as well have fixed attacks, with fighters starting at +11 and going to +30/+25/+20/+15 by level 20, wizards going from +10 to +20/+15, etc. Attack rolls would be abolished -- the defender makes an AC roll attempting to beat the fixed attack.

Although personally, I'm inclined to go in the opposite direction, making saves fixed and spell DCs variable, so that the "attacker" always rolls against the static DC of the "defender," whether the attacker is using a bow or a spell.
StevenO
01-07-08, 08:51 PM I agree with JulesCARV, the only time I'd make extensive use of variable AC is when using fixed attacks. Other than that I'd only use if for one on one duel type situations.

Using variable AC can make a DM's life a little easier for a large party. Instead of rolling attacks for all the monsters just have them "take 10.5" on all their attack rolls and then have the attacked player roll their own defense. It may not cut down the number of dice rolled but it moves the random part away from the DM and makes the players more interactive.
Dalzig
01-07-08, 10:14 PM This isn't game-breaking in any way, but it's worth mentioning the slight change in statistics.

Normal: Atk of +4, AC of 14. Attacker wins 55%, Defender wins 45%. [1-9 miss, 10-20 hit]

Variable: Atk of +4, AC of +4. Attacker wins 47.5%, Defender wins 47.5%, Tie 5%. If you declare a winner for a tie, it shifts to 52.5% vs 47.5%.

Like I said, not gamebreaking exactly. It still seems a little pointless (and time-consuming) unless your group really like the added feel of actively dodging. I personally like the idea, but a bit much work for me.

Edit: Now that I said that... I've done exactly the same thing for spells for pure flavor. I might have to run this by my group.

Post/Author/DateTime	Post
Orenmir 01-06-08, 11:15 PM	Any DMs out there use a variable instead of the standard "10+" for Armor Class? I could envision using a d20 or d10+5 or 2d10 instead. It seems logical and maybe not even game breaking. The only downside I can see is that it adds more rolling and calculating to combat time -- making it arguably too drawn out. If you do, let me know how it works for you. Do battles take longer? Do you let monsters, PCs, or NPCs take 10 on attack or AC rolls? (thread (http://forums.gleemax.com/showthread.php?t=974518) that inspired this thread)
NoldorForce 01-07-08, 01:04 AM	The primary difference is that it will increase whatever gap exists between attack modifiers and armor class modifiers. This is the general case for opposed-roll systems, that the person with the higher modifier has a much bigger chance of winning than the person with the lower modifier. This happens because the high-modifier person has a chance of rolling so high as to shut out the low-modifier person. However, the nature of making opposed rolls is that the high-modifier person may roll terribly such that the low-modifier person has a chance of success when they wouldn't under a take-10 system (as normal with attacks vs. AC).
kuonji 01-07-08, 03:58 AM	Any DMs out there use a variable instead of the standard "10+" for Armor Class? I could envision using a d20 or d10+5 or 2d10 instead. It seems logical and maybe not even game breaking. The only downside I can see is that it adds more rolling and calculating to combat time -- making it arguably too drawn out. The first question I have is, what is your problem with AC? Do you simply not like the idea of a static AC or is it a problem with players/monsters ACs being too high or too low? I wouldn't use random AC for the very reason you list, it adds more unnecessary dice rolling. If you do, let me know how it works for you. Do battles take longer? Do you let monsters, PCs, or NPCs take 10 on attack or AC rolls? (thread (http://forums.gleemax.com/showthread.php?t=974518) that inspired this thread) I wouldn't use take 10 on any combat rolls. But I would like to point out that if you move the d20 roll to AC and use take 10 on the attack roll, it's pretty much exactly the same as using a d20 to make an attack roll and taking 10 on AC (since base AC starts at 10).
Orenmir 01-07-08, 05:28 PM	The first question I have is, what is your problem with AC? I don't have a problem with the RAW or the variable AC rule. I just like to explore the options. I'd like to hear DMs' opinions on how the variable AC (or opposed rolls) works for them. Just curious; not trolling.
Tequila_Sunrise 01-07-08, 07:31 PM	Any DMs out there use a variable instead of the standard "10+" for Armor Class? I could envision using a d20 or d10+5 or 2d10 instead. It seems logical and maybe not even game breaking. The only downside I can see is that it adds more rolling and calculating to combat time -- making it arguably too drawn out. This very variant was actually presented in Unearthed Arcana. I myself prefer less die rolls rather than more, so I've never used it. (I actually turn all opposed rolls, like grapple, etc., into single rolls opposed by DCs) As to the game effect, well, more randomness nearly always works in the underdogs' favor. So big showdown fights with the BBEG will become a bit easier for the PCs, while mook fights will become a bit easier for the swarms of mooks.
JulesCARV 01-07-08, 07:33 PM	I'd say that if you were to go with variable AC, you might as well have fixed attacks, with fighters starting at +11 and going to +30/+25/+20/+15 by level 20, wizards going from +10 to +20/+15, etc. Attack rolls would be abolished -- the defender makes an AC roll attempting to beat the fixed attack. Although personally, I'm inclined to go in the opposite direction, making saves fixed and spell DCs variable, so that the "attacker" always rolls against the static DC of the "defender," whether the attacker is using a bow or a spell.
StevenO 01-07-08, 08:51 PM	I agree with JulesCARV, the only time I'd make extensive use of variable AC is when using fixed attacks. Other than that I'd only use if for one on one duel type situations. Using variable AC can make a DM's life a little easier for a large party. Instead of rolling attacks for all the monsters just have them "take 10.5" on all their attack rolls and then have the attacked player roll their own defense. It may not cut down the number of dice rolled but it moves the random part away from the DM and makes the players more interactive.
Dalzig 01-07-08, 10:14 PM	This isn't game-breaking in any way, but it's worth mentioning the slight change in statistics. Normal: Atk of +4, AC of 14. Attacker wins 55%, Defender wins 45%. [1-9 miss, 10-20 hit] Variable: Atk of +4, AC of +4. Attacker wins 47.5%, Defender wins 47.5%, Tie 5%. If you declare a winner for a tie, it shifts to 52.5% vs 47.5%. Like I said, not gamebreaking exactly. It still seems a little pointless (and time-consuming) unless your group really like the added feel of actively dodging. I personally like the idea, but a bit much work for me. Edit: Now that I said that... I've done exactly the same thing for spells for pure flavor. I might have to run this by my group.