Roll20 BECMI tips and tricks

23 Jan, 2025

Here are some practical tips and tricks on running BECMI/Rules Cyclopedia¹ or its free clone — Dark Dungeons² (or any other similar D&D game) on Roll20, based on my own experience of running a Mystara campaign.

Contents

• Jumpgate
• Character roll template
• Character sheet
• Turn tracker
• Wargaming

Jumpgate ↩

Since Jumpgate,³ the Roll20’s Improved Tabletop Experience, has been out of beta since 2025-01-06, there's no reason to stay with the legacy engine. But what if you already have an ongoing game? While there is no way to transfer an old game to Jumpgate directly, you can copy your game content into a new Jumpstart one through the "Copy Game" option in your game's settings.

Character roll template ↩

Share this Roll20 script with your players. Copy-pasting it into the Roll20 chat will roll a whole set of attributes for a new character.

--new character--
STR [[3d6]]
INT [[3d6]]
WIS [[3d6]]
DEX [[3d6]]
CON [[3d6]]
CHA [[3d6]]
Starting Gold [[3d6*10]]
----

Character Sheet ↩

The "BECMI" character sheet on Roll20⁴ is what you need. Unfortunately, it has some bugs, but currently, it's the only one specifically designed for the BECMI/RC ruleset. The main points you need to keep in mind are listed below.

Attacks

First, you should enter your THAC0 value in the top-right field of the Combat tab, lest your attack rolls produce an error. If you are using Dark Dungeons, to get the THAC0 value, subtract Base Attack Bonus from 20, e.g. BAB +1 = THAC0 19.

The Vs column of the weapon table isn't that important on the starting levels, but once you start using the Weapon Mastery rules, it will come in handy for selecting the Opponent Type. Its meaning might not be obvious, especially if you are using Dark Dungeons which has slightly different terminology, so here's what it all corresponds to:

Spell damage

The spell damage field is broken⁵ and must be stated in the double brackets form, placing the roll part, e.g. [[1d6, in the Damage Dice field, and its bonus, e.g. +1]], in the Damage Type field.

Tokens

You can tie a token to a character sheet by selecting the Represents Character field and then clicking on the Update Default Token button. Additionally, you can tie important character parameters to the token bars. Alas, you cannot do the same with the AC value due to the way the sheet is designed, so you'll need to write it in manually.

Speaking of AC, there is also some minor bug with the armor type selection⁶, but if you stick to the basic types (those that have AC numbers written in parentheses), you should be fine math-wise.

Turn tracker ↩

You can create an automatic round tracker by creating a custom item in the Turn Tracker⁷ and entering -1 in the Round Calculation field. This way, the round entry will decrease by 1 each time it is highlighted in the turn sequence. Why -1 instead of +1? This way you can sort the turn order in one click since the negative initiative rarely occurs and, after sorting, the ROUND line will appear at the bottom of the list most of the time.

If you use the "Dying and Death" rule from Dark Dungeons,² where unconscious 0hp characters must make a Death Saving Throw at the end of each combat round to stay alive with an increasing penalty to each subsequent roll, you can also represent it by entering the penalty into their turn order line (-0, -1, -2, etc.).

Wargaming ↩

Whichever tactical wargaming rules you use (we had settled on the 2nd edition of Battlesystem⁸), you can use Roll20 for this too. Start with the inch grid to place the figures (Euclidean Measurement), disabling the grid at the start of the battle. You can select multiple figures comprising a unit and move them together.

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