Most “standard” computer games get harder because they get faster, relying on the player’s reflexes and coordination keeping up. For example, in Tetris the blocks appear and drop faster and faster as your level increases:

Tetris, like most single player games, devolves into twitch gameplay as the levels increase.
Untimed games or time-independent games are those where you aren’t penalised if you play a game very slowly, have bad reflexes, or don’t posses the hand-eye coordination to time your movements accurately. Games like this are “turn-based” where any game actions only occur in response to the player’s actions, and don’t have any other timers or time-related limitations. One of my favourite time-independent games, Drop7, is another block-dropping game but each block only “falls” once you tell the game where to put it. Drop7 increases the difficulty by changing the mix of blocks which are dropped and by adding a layer of hidden (grey) blocks at the bottom of the screen after a number of moves:

Drop7 increases the game's difficulty level by changing the pieces available.
Time independent games share all of these things:
- Game pieces aren’t animated in a way that changes where you need to hit them, so taking extra time to initiate a move doesn’t cause your target to shift.
- There is no timer limiting the amount of time you can take to play each move or the time taken for the overall game.
- Being fast or slow doesn’t change the number of points awarded for each move or for an overall game.
- The app doesn’t “reset”, losing your position in the game, if the device is turned off.
If you aren’t sure if a game fits all these requirements, a good way to check yourself is to open the game and choose exactly where you’ll tap the screen to make a move … then put the device down for 5 minutes before coming back and tapping the screen exactly where you had previously decided. If there’s no disadvantage (or advantage) to your 5-minute pause that’s time-independent. If you could do the same pausing routine at any point during the game then the whole game is time-independent.
Why would you want to know if a game is time-dependent or not? There are a large number of disabilities that affect timing, most of which come under these general categories:
- Conditions that affect perception (eg vision impairment, conditions affecting how the brain interprets perceptions, sensitivity to animated movement) which may slow down how fast you understand what the game’s state is.
- Conditions that affect thinking or memory (eg brain injury, intellectual impairment, memory impairment) which may slow down your decision about which move to make.
- Conditions that affect movement or reactions in the limbs used to control the iPad (eg cerebral palsy, quadriplegia) which may slow down your ability to make the move you’ve decided to make.
An extra effect of time-independent games is that collaborative gameplay becomes possible. This could be a parent playing with a child, two friends playing together, a therapist playing with a client, or a partner-assisted play scenario where the player indicates their desires by their own methods and the partner physically touches the game devices for them.

Computer implementations of board games are almost always untimed, so they're excellent for collaborative or partner-assisted gameplay.
A surprisingly small number of games actually fit the requirements for being fully time-independent, so for this list I’m broadening the definition a little. If the game does have some time-dependent elements but these can be adjusted by the player or aren’t essential to regular play then I’ll make a note of this in the list:
- A Monster Ate My Homework! (one of my favourites!)
- Aqueduct 101
- Arcs Free
- BeeCellsHD/BeeCells Lite (one of my favourites!)
- Blocks
- Boggle (has an overall timer but player can adjust from 1 to 10 minutes)
- Bookworm
- Brain Games 3 IN 1
- The “Choice Of” series of interactive fiction games
- Doodle Fit
- Drop7 (one of my favourites!)
- Geared HD
- PatternSrch
- Sliderz HD
- Solitaire and Spider Solitaire
- Squramble
- Stone Flood (one of my favourites!)
- TradeNations (this is a simulation game of the “Farmville” or “Sims” type)
- Trism (mostly untimed, it requires quick movement of iPad’s angle for best multi-move cascades but you can play perfectly well without these)
- Word Abacus (one of my favourites!)
- Words With Friends (like online Scrabble)
These others are games that people have suggested may be time-independent, but which I haven’t tested myself:
What’s your favourite time-independent game?
- Ricky Buchanan
Ruth Ellison May 17, 2011 at 7:47 pm
Good article Ricky. My favourite time-independent game is Words with Friends.
Ricky Buchanan May 18, 2011 at 2:00 pm
@Ruth: WWF is indeed pretty cool! Feel free to look me up to play, my nickname is “jeshyr”
lyl dun May 17, 2011 at 9:30 pm
Just going through my ipod touch list of time independant apps:
Dungeon Raid
LetsTans and Tanzen(tangram based games)
Symbolism
reMovem
Unblock Me and Move it
Faces iMake (really a drawing program but its ammusing)
Angry birds (requires a swipe not a tap)
Bridge Basher
Flood it and Crazy fill
Textropolis and Fishtropolis (word games)
Yatzy
iCut
Trainyard
Canasta
Rummy
[I'm starting to think I spend too much time playing on my ipod]
Ricky Buchanan May 18, 2011 at 1:59 pm
@Lyl: Oh thank you, that list is fantastic! Is Flood It/Crazy Fill like Stone Flood? I did nearly add Angry Birds to the list but I find it really difficult to play because of the swipe, so in the end I left it off … it’s great to have more for people to know about though!
@thorfi May 24, 2011 at 8:42 pm
Angry Birds also requires timed taps for some birds at higher levels, so it’s definitely not timing free.
Dungeon Raid is new, and very awesome.
There’s a free basic version as well as a more complicated non-free version.
Kati May 17, 2011 at 9:41 pm
which Mah jongg game is that shown in the pic?
Ricky Buchanan May 18, 2011 at 1:58 pm
@Kati: Ummm, I think it’s Mahjong Epic HD Lite but I’m not 100% sure. It’s definitely a free one though, so let me know if you find it!
Paul Natsch May 18, 2011 at 1:53 am
Great article Ricky! Probably Words with Friends, Scrabble, and Civilization (preferably IV).
Ricky Buchanan May 18, 2011 at 2:04 pm
@Paul: Ohh, Civilization wasn’t one I knew about – thanks! I haven’t ever played Civ although I’ve heard of it. Thanks.
Kerry May 21, 2011 at 9:00 am
Thanks for mentioning time-independent games! I thought I was weird for years because I wasn’t able to play timed games because I couldn’t process the events quickly enough—autistic-related stuff—and I’d end up losing because of them. It’s the reason why I don’t play a lot of computer games other than simulation ones—you don’t have enough time to work things out, and you’re always trying to manage the game while dealing with the strict time constraints that frankly aren’t meant for people with those sorts of processing difficulties.
Ricky Buchanan May 22, 2011 at 12:59 pm
@Kerry: You’re not weird! Well, no weirder than a lot of other people, anyway. I never enjoyed computer games either although I’m not actually really bad at them I just prefer games that rely on thinking not reflexes!
Patrick Black June 29, 2011 at 1:03 am
Ricky,
Check out Shape Shifter, a puzzle type game, but I believe it is time independent. Free Too!!
Patrick
Todd January 3, 2012 at 5:06 pm
Great article – I find these games far more relaxing!
SpellTower is similar to Drop 7 but using words instead of numbers. Very minimalist and highly recommended.
Ricky Buchanan February 14, 2012 at 12:04 pm
Wow, thanks Todd! I just downloaded SpellTower yesterday and it’s heaps of fun!