Mobile roguelikes - UI, design and the Android landscape

Tom Ford

Oxford, United Kingdom

IRDC 2012 London

My roguelike games

• 2009 7DRL: DDRogue – Special attacks linked into normal

movement

– Narrative amnesia plotline with multiple endings

• 2010 1KBRL: ZigClimb – Armour and weapons

– Positioning and MvM combat important

• 2010 7DRL: PrincessRL – Successor to DDRogue (same engine)

– ‘Class’ differentiation through point-based training choices

– Limited (12) opportunities for short (3 level) dungeons in ~2 hr game duration

– Magic and charm in addition to special moves give role differentiation

– Narrative plot, unusual setting and multiple endings http://flend.net

Mobile (Android!) roguelikes

• Google Play search for ‘roguelike’

gives you:

• 36 hits

• 27 unique games

– 2 in Japanese!

• 22 roguelikes

• 18 non-desktop ports

Mobile roguelike game design

• Good game design is good game design regardless of platform

• Mobile devices (particularly phones) bring their own challenges /

opportunities

– Touch interface

– Limited screen size

– Device speed

– Heterogeneous devices

– Usage models

– Low Barrier to entry

– App Stores

– Remuneration models

The touchscreen

• How can we use the touchscreen for a roguelike on a phone or

tablet?

– Can we adopt the evolving conventions of touchscreen usage?

• Should we

– Pretend it doesn’t exist?

– Tolerate it?

– Embrace it?

D-pad tap

(Endless Depths)

D-pad slide

(VOYAGE TO FARLAND)

9 directions

(ROGUELIKE CLASSICS)

Directional tap

(ROGUE TRIAL)

Drag to scroll

(DWELLER)

Slide to move

(TRAQUE HACK)

Tap to travel

(LEGENDS OF YORE)

Pinch to zoom

(NETHACK)

Travel after pan

(NETHACK)

On-screen keyboard

(ROGUELIKE CLASSICS)

Hold to run

(NETHACK)

Control methods in mobile roguelikes

Touch interface pros and cons

• Slow for repeat moves

• Lacks accuracy

• Obscure-able

• Fatiguing

– Excessive number of taps

– Excessive finger travel

• Fast for large movements

• Allow for new / natural

interactions

PROS CONS

On-screen keyboard

• As seen in

– Roguelike Classics

– No Way But Down

• Advantages

– Accurate

– Quick

– Flexible

• Disadvantages

– Obscures half the screen

– Standard on-screen keyboards often lack

particular keys on default display

– Need to know vi-keys

• Or custom set used

• Touch for non-roguelike players

PRETEND IT

DOESN’T EXIST!

On-screen D-PAD

• As seen in

– Infinite Dungeon

– Voyage to Farland

– Powder (apparently!)

• Advantages

– High(ish) accuracy

– Limited finger travel

– Rapid repeating

• Disadvantages

– Deeply conservative!

– Screen real estate dedicated

to D-Pad

– Slow for menu screens

VOYAGE TO FARLAND

PRETEND IT

DOESN’T EXIST!

Directional tap

• As in seen in

– Dweller

– Endless Depths

– Nethack

• Advantages

– Large area to tap

– Good accuracy

– 1 square movement can’t go *that*

wrong

• Disadvantages

– Possible to make mistakes if you click

close

– Feels like you are attacking behind the

monster if you click far

– Fatiguing

4 directions

8 directions

NETHACK

TOLERATE IT!

Click square to travel

• As seen in

– Legends of Yore

– Dweller

• Also directional tap

– Nethack

• Only after drag-to-scroll

• Advantages

– Great for backtracking

– Works well with drag-to-scroll

• Disadvantages

– Easy to make mistakes if squares are small

– Mistakes during combat can have serious

consequences

– Requires intelligent interruption system

LEGENDS OF YORE

EMBRACE IT!

Slide to move

• As seen in

– TraqueHack

• Fun version of directional tap

• Not as tiring as you might think

TRAQUE HACK

Tap and hold to run

• As seen in

– Nethack

• Typical alternative to double click

• Delay makes it irritating compared to

double tap

NETHACK

EMBRACE IT!

Screen size

• Mobile screen size average 8 cm x 5 cm

• How many tiles to pack in?

– Dweller (small tiles): 14 x 20 -> 3 mm x 3 mm

– TraqueHack: 5 x 4 -> 15 mm x 15 mm

• Large tiles are better for accuracy

– Personally: 5 mm x 5 mm safe minimum

• Excessive scrolling for ranged-attack heavy

games

• Game design consideration

Zoom

• Pinch to zoom typical mobile

interaction

• Nethack port uses this to good

effect

– Great for backtracking

Unexplored features:

• Oversized monster & item & stair

icons on zoom out

• Autozoom out to show all in-vision

targets

Targetting

• Rogue-style 8 directions

• Legend of Yore

– Click to shoot for Wizard

• Dweller-style targetting

– Click ranged attack to enter mode

– Click again to fire / cast

– Reticule automatically moves onto

next target

– No autoclose

Gestures

• Useful in archery and magic systems?

– rgrd discussion

TAP TO MOVE / MELEE DRAG TO SHOOT /

CAST READY SPELL

Archery gestures

• Are you going to trust your mage or archer’s life to these?

Items, Inventory and Menus

• Click on yourself seems to be a natural motif for ‘interact with whatever I’m standing on’

• Menus, inventory or otherwise seem slower on mobile than PC, with lots of finger movement

• Auto-pickup, auto-equip, current item comparison all help

• Quickslots for spells and potions help to integrate most actions into the main screen

– Replacement for keyboard chord motif

• Overlays gel better than menus

ENDLESS DEPTHS

App Stores, Advertising and Remuneration

• Nowadays it’s no longer taboo to make money from roguelikes!

– More or less

• Free & Paid app strategy

– In game payments

• Importance of marketing / community building

• Niche or mainstream pricing strategies

– Legends of Yore: $2

– Trap Rogue: $6

• Delver donation model

• Donation via paid apps

100,000+

50,000

10,000

5,000

1,000

500

?

Dec ‘09? Jan ’09?

Apr ‘09 May ’09?

May ’09?

Mar ‘12 Jan ’09? Jun ‘11

Ascendances

Downloads

Nov ‘09 Jun ‘11

A graph (of contentiousness)

Rogue DIABLO

IBM PC

ONE X

TRAQUE HACK

NETHACK LEGENDS OF YORE

FARLAND

HYDRA SLAYER

DWELLER

INFINITE DUNGEON

SIGMORE MINES 2

HYPER ROGUE

ROGUE TRIAL

ENDLESS DEPTHS

Quest Swords and

Spells

NO WAY BUT DOWN

TRAP HUNTER

DELVER

Kamyran's Eye

ANDOR’S TRAIL

SAMURAI ROGUE