Link to the Alpha: https://proteus236.itch.io/duelo

How it started

When I started working on Duelo, I asked myself a simple question:

What would happen if the randomness and excitement of ARPG loot drops collided with the depth and strategy of competitive card games like Magic: the gathering or Yu-Gi-Oh?

This question became the foundation of everything.

At its core, Duelo is an experiment.

I'm blending two very different design philosophies:

• Strategic, skill-based card gameplay (inspired by classic TCGs)
• Unpredictable, high-stakes loot systems (inspired by ARPGs)

The result?

A Roguelite Card-Looter where your deck isn’t just built… it evolves, mutates, and sometimes even betrays you.

The ARPG Soul: Loot, But It’s Your Cards

In most card games, progression is predictable:  You unlock cards → you build a deck → you optimize.

Duelo flipped that idea.

Instead of farming items… you farm card transformations.

Every card in your deck can be permanently corrupted, gaining:

• New keywords and mechanics
• Increased power, range, or multi-hit potential
• Chain effects or unexpected interactions
• Risky downsides that can completely change your strategy

Each corruption works like a loot drop roll.

You might create a game-breaking combo… Or a card that’s too dangerous to use.

Strategy Still Comes First

Even with all this randomness, Duelo is not chaos.

Combat is deeply tactical:

• Your hero is always on the battlefield
• You summon, attack, defend, and position units
• Every turn demands timing, resource management, and adaptation

This isn’t just about drawing the right card — It’s about making the right decision under constantly changing conditions.

A Run That Shapes You Back

Every run in Duelo is a journey through a branching map full of unpredictable encounters.

But here’s the twist:

Encounters themselves can mutate.

• Enemies gain unexpected modifiers
• Rules change mid-run
• Familiar fights become completely different challenges

You’ll constantly face meaningful decisions:

• Do you take the safe path and preserve your deck?
• Or chase high-risk nodes for powerful corruptions?

A Card-Looter, Not a Deckbuilder

One of the biggest shifts in Duelo is how progression is treated:

• Cards you earn go into your collection, not directly into your deck
• Your deck is something you craft between runs, not during them

This creates a hybrid system where:

• Runs are about mutation and survival
• Meta-progression is about strategy and mastery

Building on the Duelo Universe

The version of Duelo you’re seeing here is part of something bigger.

The artwork currently used in the game comes from the physical card game, which was independently published in Peru. This videogame is a new product within the Duelo universe (which also includes a comic).

Because of that, you might notice a mix of styles or incomplete visuals — and that’s intentional (for now).

• Much of the current art is being used as placeholder
• New illustrations are actively being developed to match the evolving vision of the game
• The goal is to unify everything under a stronger, more cohesive visual identity

This means you’re not just watching a game being built — you’re watching an entire IP grow and evolve across multiple formats.

What can you find in this Alpha?

This early version of Duelo already includes a solid slice of the core experience:

• A 6-floor map to progress through
• 6 different types of encounters across the map
• 46 different base cards/items to unlock
• Thousands of possible permutations for each card thanks to the corruption system
• And when you finally defeat the final boss... Well, that’s something you’ll have to discover for yourself.

What do you think about this experiment?

Duelo is being built with experimentation at its core — and your feedback is part of that process. If you think this concept is interesting, I’d love to hear your thoughts. 

- Eduardo M.

Link to the Alpha: https://proteus236.itch.io/duelo

Devlog #2 - How Do You Build Co-op in a Roguelite Card Game?

Since I started working on Duelo, one question kept coming back again and again:

How can I make this game playable in co-op?

The Challenge

This is my first time developing a videogame… and also my first time building online multiplayer.

So from the beginning, I knew one thing:

I shouldn’t overcomplicate it.

The most obvious approach would be a fully synchronized battlefield:

• Players sharing the same board
• Seeing each other’s heroes and units
• Interacting with the same space in real time

But there was a problem.

Duelo was designed from the ground up as a single-player experience.

Trying to retrofit full synchronization would mean:

• Reworking core combat logic
• Rebuilding systems that assume a single player context
• Increasing complexity a lot for a solo developer

So I asked myself:

What’s the simplest version of co-op that still feels meaningful?

The Inspiration: Raid-Style Co-op

The answer came from an unexpected place: raid systems like the ones in Pokémon Go

Instead of forcing players into the same battlefield, the idea is:

• Multiple players join a shared lobby
• Everyone fights the same boss
• But each player plays their own instance of the battle

The key?

The only thing that’s synchronized is the boss’s health.

No need to sync units. No need to sync boards. No need to sync complex interactions.

Just one shared objective.

Duelo Co-op Proposal

Here’s how co-op could work in Duelo:

• Up to 4 players join a lobby
• A random boss is selected, along with a set of mutators to make the fight challenging
• Each player selects the deck they want to bring

When the battle starts:

• Every player fights the boss in their own isolated match
• You won’t see other players’ cards, heroes, or units
• You only interact with your own battlefield

But…

• The boss’s health is shared across all players
• If one player reduces the boss HP from 80 → 70 → everyone sees that change in real time

This creates a sense of cooperation without the technical overhead of full synchronization.

Why This Approach?

For a solo developer, this approach has huge advantages:

• Much simpler networking logic
• No need to redesign the entire combat system
• Scales better for early testing and iteration

But more importantly… It still creates tension and cooperation:

• You’re racing against time and against failure
• Every player’s performance matters
• If one player dies, the entire party is Defeated.
• Victory is shared — and so is defeat

What Do You Think?

This is still an evolving idea, and your feedback really matters here.

• Does this kind of co-op make sense to you?
• Would you find it fun or engaging?
• Would you prefer a more traditional synchronized system instead?

I’d love to hear your thoughts as I continue shaping this feature.

Because just like everything in Duelo… this system might evolve in unexpected ways.

Devlog #3 — Co-op Progress Update: Making It Truly Cooperative
Hey everyone!

I wanted to share a quick update on how co-op multiplayer is evolving in Duelo — and things are progressing really well.

From Shared HP… to Fully Shared Boss State

In the previous devlog, I talked about a simpler approach to co-op:

• Each player fights the boss in their own instance
• Only the boss’s health is synchronized

That was the plan. But as development moved forward… things got more interesting.

I’ve taken it a step further:

Now, all boss stats are fully synchronized across all players.

This means:

• Any action performed on the boss is shared
• All Stat Modification, Auras and Curses are synchronized in real time
• Every player sees the same state of the boss

Real Cooperative Synergy

This change makes a huge difference in how co-op feels.

For example:

• A player running a Bludgeoning damage build manages to stun the boss
• That stun is now applied globally
• All players can take advantage of that window

Suddenly, you're not just fighting “alongside” others… You’re actually working together.

This pushes Duelo closer to the original fantasy:

A true cooperative experience where builds complement each other

Scaling the Challenge

The current plan is to support up to 4 players in co-op.

And to keep things balanced (and challenging):

• The more players in the lobby → the more mutators the boss will have

This ensures that:

• More players = more power
• But also = more difficulty

So coordination and build synergy will matter even more.

About the Multiplayer Build

There’s an important technical note to share. Duelo’s multiplayer is currently being developed using:

• Steamworks (via Facepunch)
• Steam’s networking architecture

Because of this…

It’s very likely that the co-op multiplayer build won’t be released on itch.io

Instead, the plan is to release it as a demo on Steam.

This will allow for:

• Better stability when testing online features
• Easier matchmaking and lobby systems
• A smoother overall multiplayer experience

What’s Next?

There’s still a lot to polish, but this is a big step forward.

I’ve gone from a “parallel play” co-op idea to something that actually feels like:

Players influencing the same battle together

As always, I’d love to hear your thoughts.

Does this direction make the co-op more appealing to you?

- Eduardo M.