Herebelow are 3 magic items from the 3.0/3.5 DMG, converted to 5e:

Potion of Barkskin

Potion, uncommon

When you drink this potion, you gain the effect of the Barkskin spell for 1 hour (no concentration required) or until you end the effect as a bonus action. This potion’s liquid looks like stagnant water with pieces of bark floating. When ingested, the bark dissolves as it exits the potion.

Wand of Mage Armor

Wand, uncommon

This wand has 15 non-rechargeable charges. While holding it, you can use an action to expend 1 of its charges to cast the Mage Armor spell from it.

Once all the charges have been expended, the wand crumbles into ashes and is destroyed.

Elemental Gem

Wondrous item, rare

This gem contains a conjuration spell attuned to a specific Elemental Plane (Air, Earth, Fire or Water). When the gem is crushed, smashed, or broken (as a standard action), an elemental appears within 10ft. The elemental is under the control of the creature that broke the gem for 1 minute and will disappear after that. Controlling the elemental require giving direction similar to a ranger’s companion: the elemental will move where commanded (no action required to command), or Attack, Dash, Disengage, Dodge or Help at the expense of an action from the commanding creature, to be verbally instructed.

The coloration of the gem varies with the type of elemental it summons. Air elemental gems are transparent, earth elemental gems are light brown, fire elemental gems are reddish orange, and water elemental gems are blue-green.

Little does she know that the fees she has paid have been hijacked by the harbourmaster’s trusted agent, Soller Vark, and that the boat has been moored further in they bay and is being used by a band of smugglers to trade exotic animals and led by Soller Vark himself.

Though Lavinia advocates for a soft solution, the PCs will most likely end up fighting the smugglers and their leader.

In terms of encounter and considering the scenario was designed for 1st level characters, it was already challenging for D&D3.5, consisting on two APL+1 encounters in a row (3.5 CR of 2 & 2).

When it comes to D&D 5e, all APL considerations are gone. Instead, 5e uses a measure of XP per PC, and difficulty level ranging from Easy to Deadly, in four categories and explained page 81 of the DMG.

For 4 1st-level characters, the range is:

• Easy encounter goes for 25 XP per PC. The PCs should have minimum trouble to overcome this encounter, and use little resources to do so.
• Average encounter goes for 50 XP per PC. At this difficulty level, the PCs’ resources should be used sparingly, and they should be able to handle 6 to 8 of these between long rests.
• Hard encounter goes for 75 XP per PC. Things start getting spicy here, and chances are that one character may hit the dust, and that substantial resources will be used to overcome the encounter.
• Deadly encounter goes for 100 XP per PC. One PC will certainly drop, and the others may end up in a difficult position as well. This difficulty is better suited for final encounters.

Another consideration lies in the number of opponents, and the reason is: the more opponents, the more potential attacks on one PC. The original 3.5 version goes for 6 “thugs” for the first wave. However, with 6 opponents, the encounter XP has to be multiplied by 2, as per the DMG guidelines on page 82.

A Hard Encounter for 4 1st-level PCs has a total XP threshold of 300:

Which, for 6 opponents, translate into an individual XP of 25:

Reading through the DMG’s encounter creation guidelines, this translates in an individual CR of 1/8.

Instead of creating a creature from scratch, I took the bandits’ stat block from the MM and changed their equipment to match the scenario’s original.

For the second wave, the scenario had Soller Vark as a CR 2 for edition 3.5, and the last “thug”, a female named Ketrana who was sharing his bunk.

Being an above average opponent, I chose to aim at another Hard Encounter for him and his partner, but he would take the bulk of the 300 XP threshold. A CR 1 opponent has an XP value of 200, and a CR 2 opponent is valued at 450. No choice here, I had to limit myself to a CR 1.

To convert Soller Vark, and because he was a Fighter/Rogue in 3.5, I cranked up the bandit a bit for  the bandit captain described in the MM would be of a too high challenge, and I needed someone who would share some traits with his men.

The DMG provides a whole section on creating new monsters. Essentially, it is a mix between durability (hit points, immunities and resistances), defensive abilities (AC), and offense (average damage in one round).

To meet my CR 1, I ended up increasing his Hit Dice, giving him a slightly better armor, and granting him a second attack to meet the damage output of a CR 1 (9-14 damage per round).

This second wave ended up with an XP value of 225, slightly above an Average Encounter.

The two waves had been converted, but I needed to pay attention not to overwhelm the PCs. Thankfully, the scenario had all these NPCs in different areas of the ship. I ended up scheduling their arrival on the bridge to fight the PCs.

Here are the stat blocs for the Blue Nixie’s crew: Blue Nixie Smugglers Crew 5e.

The encounter went well for my group. The PCs’ were able to manage the two successive waves and spent about 2/3 of their 1st-level spell slots, with minimal Hit Points loss.

Though they had managed to subdue Soller Vark and two surviving smugglers, they let their guard down which allowed the remaining smugglers to dive overboard and escape.

Next time, I’ll look into the Ragodhessa’s conversion.

The drawback to it was that some of his buddies had bought the latest D&D edition, and all of my material was 3.0/3.5. Either I was going to teach them the ropes of material they did not possess, or I was going to jump to the latest edition. I ended up ordering the 5e books.

Fortunately, I was already tied the weekend they hoped to play, which gave me a little respite to get prepared. In under three weeks I had to read the new rules, select a scenario and get things rolling!

My choice ended up on adapting the Savage Tide arch published through Dungeons magazine 139 to 150 for its swashbuckling and tropical mood, culminating with an encounter against Demogorgon himself.

The first scenario’s tempo is split in two parts:

1. Getting involved. Lavinia Vanderboren hires the PCs to retrieve an heirloom signet ring that will open the family’s coffers.
2. The PCs get head-first in trouble with a local thieves’ guild supported by Lavinia’s brother.

Since it was the last arch written for Dungeon magazine before Hasbro/Wizards of the Coast ended the publishing deal, it also means that the scenarios follow the 3.5 ruleset, thus a need to convert to 5e.