The Planar Vagabond's Guide to the Multiverse

Escape the O.V.T.!

For 2026, rather than making yet another pass at Ravenloft, I thought it might be time to change it up a bit…

On the distant plane of Ayreon, in the land of Kalar, it’s harvest season again. But this year, a shadow hangs over the festivities…

In the small town of Grimpost, ten villagers have gone missing in the past few weeks, all disappearing without a trace.

The only clue anyone can find comes from the last time something like this happened, nearly 30 years ago - a rough map leading to a cave a few miles outside of town, marked with the words “Entrance to the O.V.T.”

And so, our party of adventurers has come to the cave searching for the missing villagers. But what horrors will they find inside? And will any of them survive long enough to…

Escape the O.V.T.!

This will be a 4-5 hour one-shot for a party of 3-5 level 4 adventurers, with (what should be) a mostly survival-horror vibe (with a bit of comedy thrown in for good measure). As usual, I’ll be running it using the HOSR system. Everyone can pick any available race and class from Planar Vagabond, Old School Essentials, or any other B/X-compatible system for their character, and every character will start with two magic items (rolled randomly ahead of time).

So, do you have what it takes to face the challenge of the unknown and… Escape the O.V.T.?

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Most of the rules will be the same as the past few times we’ve played, but I would like to introduce one new rule during this one-shot, the Combat Countdown Timer, inspired by this article (found via Questing Beast).

Combat Countdown Timer

At the start of the first round of combat (before anything is declared or initiative is determined), the GM rolls 1d4+2 and shows the resulting value on the board (ex: with a d6) as a “Combat Countdown Timer”.

• At the start of each subsequent round, the combat countdown timer is decremented by one.
• If the combat has not finished by the time the countdown timer reaches 0, the GM determines the winning side based on how the battle has proceeded.
  • If the PCs lose, overwhelming opposition reinforcements could arrive, or some environmental effect could occur that definitively ends the combat in the opposition’s favor.
  • If the PCs win, it’s similar to a failed morale check (the opposition is routed), or some environmental effect could occur that definitively ends the combat in the PC’s favor.
  • In the (hopefully rare) case of a draw, dice can be rolled, or the combat could end with no clear winner (ex: with both sides cut-off from each other).

Magic Item Tables

1. Pick 2 of the first 3 tables below (or the same table twice).
2. For each table, roll the indicated die, look under the result, and either pick from or roll on the linked table (further below).

Linked Tables