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Hydra Slayer for Android

Hydra Slayer v13.0A by Zeno Rogue <zeno@attnam.com>, released under GNU General Public License version 2

This is the version of Hydra Slayer for Android devices. Hydra Slayer is a roguelike (that is, a game where you control a single hero fighting horde of monsters, with a high emphasis on tactics) where combat has been inspired by some mathematical puzzles about brave heroes slaying many headed beasts. Note that this might look like a standard dungeon crawler, but the puzzle element is important, and the later game is meant to be challenging. Try the tutorial first! If you find any bug, or find that the tutorial does not explain everything it should, please send me a report instead of just uninstalling! I'll consider it for the next version.

Android Controls

The story

Hydra slaying has a long history.

First explorers who have met hydras were completely unable to do any harm. As they cut hydras' heads, two new heads always grew in place of each one cut.

Some of them started using clubs instead of swords. However, this was only a temporary solution. A club may stun a hydra, and make it temporarily less dangerous, but not kill it. When time comes, it will wake up and attack further. Hydras remained indestructible monsters.

Some mages have been employed to research methods of slaying Hydras. The first thing they have invented were Runes of Decapitation, which could kill a completely stunned hydra, or permanently destroy some heads of a non-completely stunned one. Another thing were Runes of Cancellation, which could remove hydra's regenerative abilities. However, both of these Runes were one-use items and very expensive to create, and thus not practical.

, Then, a report came, claiming that heads won't regrow if the sword was put on fire. Apparently all Hydras in some region were killed using that method. Their meat was found extremely tasty, their blood good for healing wounds (due to hydras' natural regenerative abilities), and their scales good for improving armors.

Mages tried this method. Unfortunately, it did not work for them, though. However, they have experimented with other kinds of magically imbued weapons. It turned out that some enchantments will reduce the number of heads regrown. Possibly even no heads will regrow. Some hydras could be slayed after these findings, but not all. It is rumored that some mage long ago created a weapon which could slay any Hydra without regrowing heads, but he got overconfident and killed, and the secret was lost.

Mages experimented with their magical weapons even further. And they had a new result: weapons which could cut (or stun) several heads at once. If they cut all heads, the hydra was killed. If not, the Hydra would usually regrow the same number of heads as if only one head was cut. The mages were happy with that major result.

Of course, some new hydra slaying weapons and magics were created later, but they were nothing compared to the previous major achievement. The numbers of Hydras kept decreasing, and finally, they disappeared, and were almost forgotten... And less and less people became acquainted with the hydra slaying techniques, as other people laughed at them, because their profession was completely useless in these times.

Now you, a young student, have heard about a manifestation of hydras in so called Hydras Nest. Apparently some brave knights came to kill the Hydras... Brave, but stupid. Even if they equipped themselves with mighty hydra slaying weapons, they had no knowledge about how to use them correctly. What use is a mighty sword which can cut ten heads in one swipe, against a Hydra which has only 9 heads? All these knights have been killed.

You are more clever. Since your earliest years you have had an unnatural ability to count people in an instant, and your great grandfather has suggested you to pursue the Hydra Slayer career, and learn the forgotten art of Hydra Slaying. Now, you will show people that it is not just an useless funny thing. You take two small magical weapons and some magical items, hoping to rob better ones off dead bodies of these stupid knights, and head to Hydras Nest. Of course, not that you are one of these clever guys who are too scared and weak to be useful in a battle... you could also wield a two handed weapon with one hand.

See the homepage for the PC version of Hydra Slayer for more information and a beginner's guide.

Using the Keyboard

Since this is an Android port of a desktop game, most commands can be also activated with keyboard. You can play solely with touchscreen though, or mostly with hardware buttons and with touchscreen occassionally (well, unless you want to rename your character). In most cases the game displays the key that can be used to activate a command. (Note: long pressing the Menu button displays the onscreen keyboard on some devices.)


In the main menu, you have an option to choose your geometry. Your options are: (4) allow only horizontal and vertical movement, (6) simulate a hex board, (8) allow movement in all directions. You change the selection by pressing D, Space, 4, 6, or 8. Press '3' to create a game with variable geometry.

Your selection affects what directions are available to all actions, including your movement, hydra movement, missile weapons, grids targetted by Power Swipes, and so on. Additionally, (6) makes levels smaller (because only each second character is used) and (4) makes Hydras better at smelling you (for balance reasons).


If you are too bored to explore the Hydras Nest yourself, you can do automatic exploration. It only works if there is no enemy in sight, and will try to do the following, in order:

- pick up an inventory item you are standing on (unless a Troll),
- go to the nearest inventory item not behind mushrooms,
- go to the nearest non-explored space not behind mushrooms,
- go to the nearest inventory item through mushrooms,
- go to the nearest non-explored space through mushrooms,
- go to the stairway down.

Social Features

Version 13.0a of Hydra Slayer has a Social version. This is a separate application which includes third-party social features, and it can be downloaded from the Android Market. However, the Social version is no longer supported in 14.0.

HeyZap provides checkins, which tell your friends that you are playing Hydra Slayer, and what has happened. So, if you win a game, or simply find a nice weapon or a particularly nasty Hydra, a message is generated, which you can easily post it to HeyZap.

Swarm provides global leaderboards and achievements. You should be shown a login screen when you start the game, and then to access Swarm, simply press Menu and "Swarm". Since Swarm does not allow long names for leaderboards, here is an explanation:

More information

Savefiles and scorelists are written to /hydroid/ on your SD card. The savefile format should be compatible with the PC version, so you can start on one device and continue on another.

In case if Hydra Slayer fails to start, this is probably caused by a corrupt savefile. Just delete /hydroid/hydra.sav on your SD card. (This should not happen, but I write just in case.)

Hydra Slayer for Android (version 14.0) can be downloaded from the Android Market. It is released under GNU Public License version 2, and thus it comes with absolutely no warranty.

You can also download the source (Hydra Slayer for Android 15.0) or the APK: Hydroid.apk.

If you like Hydra Slayer, please consider donating.

You can contact me at zeno@attnam.com, or at RogueTemple forums, or at my blog (where I will publish future releases of Hydra Slayer).
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Thanks to Slashie for hosting this at RogueTemple!
@ Zeno Rogue Games @ Vapors of Insanity @ Necklace of the Eye @ [ Hydra Slayer ] @ HyperRogue @ Untahris @
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