I need help with a 2e AD&D Macro

Hi all,  I've got a macro I picked up here for Melf's acid arrow that rolls the attack based on $PC_THAC0, which is all fine and well as long as the caster is a solo class. Here is the line from the macro that works for that: &{template:2Eattack}{{title=@{selected|token_name} makes a Missile Attack!}}{{sub-title=vs. @{target|token_name}}}{{weapon_used=Melf’s Acid Arrow}}{{ac_hit=[[@{selected|PC_THAC0}-((D20)))]]}}{{dmg_s=[[2d4]]}}{{dmg_l=[[2d4]]}}{{crit=None}}{{fumble=Caster is way off target.}} However, I'd like to change it so it will be useable by multi-class casters as well, and thought by replacing PC_THAC0 with 21-(ceil(@{level}/3)) this would automatically figure the correct THAC0 for the Wizard level. I though it should look something like below, but was incorrect. &{template:2Eattack}{{title=@{selected|token_name} makes a Missile Attack!}}{{sub-title=vs. @{target|token_name}}}{{weapon_used=Melf’s Acid Arrow}}[[{{ac_hit=21-(ceil(@selected|level/3))}-((D20))]]}}{{dmg_s=[[2d4]]}}{{dmg_l=[[2d4]]}}{{crit=None}}{{fumble=Caster is way off target.}} 21-(ceil(@{level}/3)) does work by itself with our sheet to determine THAC0. Could one of you fine folk please help me get this working?   Thanks!

I don't know the answer but I admin a Discord for AD&D 2E Roll20 players & DM's, if you want to ask on the 2E Tavern discord, just PM me a request and I'll invite you in to it. There is also a 2E Tavern roll20 game, which is in the LFG.

&{template:2Eattack}{{title=@{selected|token_name} makes a Missile Attack!}}{{sub-title=vs. @{target|token_name}}}{{weapon_used=Melf’s Acid Arrow}}[[{{ac_hit=21-(ceil(@selected|level/3))}-((D20))]]}}{{dmg_s=[[2d4]]}}{{dmg_l=[[2d4]]}}{{crit=None}}{{fumble=Caster is way off target.}} has a couple issues in the syntax. Misplaced "[[ {{" and a missing {. Try this; &{template:2Eattack} {{title=@{selected|token_name} makes a Missile Attack!}} {{sub-title=vs. @{target|token_name}}} {{weapon_used=Melf’s Acid Arrow}} {{ac_hit=[[21-(ceil(@{selected|level}/3))-(D20)]] }} {{dmg_s=[[2d4]]}} {{dmg_l=[[2d4]] }} {{crit=None}} {{fumble=Caster is way off target.}}

Doh! That was it. Thank you! 

LordLollygag . said: replacing PC_THAC0 with 21-(ceil(@{level}/3)) this would automatically figure the correct THAC0 for the Wizard level. I though it should look something like below, but was incorrect. Thanks! You are using the wrong scaling for Melf's Acid Arrow. Here is the description: By means of this spell, the wizard creates a magical arrow that speeds to its target as if fired from the bow of a fighter of the same level as the wizard. This means you should use the Fighter's THAC0 table, which using the formula  (21-@{level}) So whatever level your character is goes in there in the formula. If you are a multi-class / unrestricted dual-class then you take the level of your wizard class and put in there. Even if your multi- /dual-class has a rogue class of a higher level than the wizard, you should still use the wizard level for calculating THAC0. Good luck in your games. Hope you get the macro to work!

Peter B. said: You are using the wrong scaling for Melf's Acid Arrow. Here is the description: By means of this spell, the wizard creates a magical arrow that speeds to its target as if fired from the bow of a fighter of the same level as the wizard. This means you should use the Fighter's THAC0 table, which using the formula  (21-@{level}) So whatever level your character is goes in there in the formula. If you are a multi-class / unrestricted dual-class then you take the level of your wizard class and put in there. Even if your multi- /dual-class has a rogue class of a higher level than the wizard, you should still use the wizard level for calculating THAC0. Good luck in your games. Hope you get the macro to work! Your phrasing here confuses me. First you quote where it says to use the Wizard THAC0 (which is what  21-(ceil(@{level}/3)) does), then you say I should use the Fighter THAC0, which is not what the spell says, then you go on to say that all multi-class characters should use the wizard level, again which is why I'm using the  21-(ceil(@{level}/3)) formula.  Could you clarify for me, please? Thanks!