Welcome to this week’s blog club. This week we are looking at “What is the Best Combat Algorithm?” from 2009 by Daniel Collins (Delta’s D&D Hotspot).
Next week we’ll take a look at “The Natural Mutations of a Campaign” by Trollsmyth.
You can see a list of previous blog club posts here.
I’ve used all but the humorous examples, but I don’t have a strong preference. I’ve also played THAC0 variants where players state the lowest AC their attack hits (I rolled a 16, so I can hit down to AC 3) and one where players tell the DM their total to compare to a table.
The bigger differentiator for me is actually the number of modifiers everyone has to contend with. I recall D&D 3.5 had quite a few potential modifiers to add together (attribute modifiers, magic or masterwork weapon, wield a weapon with two hands or two weapons, charge bonus, flanking bonus, feat modifiers, modifiers for iterative attacks, etc.). You could usually precalculate them so you had a single modifier to apply to a roll, but it was annoying when you had to adjust it situationally.
I haven’t encountered the Target 20 formula in play anywhere but Kevin Crawford’s Godbound, but I liked the simplicity of a static target number. If the DM didn’t want to tell players the enemy AC, they could have players announce their result so the DM can add it. Obviously, if they get 20+ before then, they know they hit (negative AC was quite rare or unused).
Systems that eschew to-hit rolls aside, I think Whitehack does it best: roll under Attack Value but above Armor Class—no arithmetic required.
I note this post is from 2009 - and in that alone it’s refreshing as it feels like it came before “THAC0” was a contemporary game shorthand for “weird out of touch old gamers” or “why old systems are dumb and impossible to understand”. Besides that I don’t care at all about these kinds of number crunching, though if I ever did or could ever be brought to Delta would be the blogger to do it.
This was the first place I ran into the Target 20. I’ve not used it because I still just reference the 1e attack matrices when I GM. Were I to run other systems without referring to 1e matrices, I’d likely use Target 20. the players need only roll and add their level bonus, then I can add in AC and other mods easily enough to call a success or fail.
I remember at the time being very excited about these developments and what would become Target20, which I utilized for years, until I slipped back into the comfort of just using thac0.