# why ARS has rotation blocking for J, L, T...

Thread in 'Strategy' started by farter, 26 Apr 2012.

1. ### farter

i just got mad about it 2 years ago (i don't know about SRS then), so i made my XRS which allows this rotation...

Code:
......  ......  ..()..
[][][]  [][][]  ..[]..
..()[]  []()..  [][][]

well now i'm still guessing why there's such weird restriction for JLT...
....if what what is occupied, it does not rotate; but if what what is also occupied, it rotates...

here's what i guess...

because the wallkick order is (original, right, left), but not related to the direction of rotation, under the following situations (which appear very often), it will become...
Code:
........  ........  ..()....  ..()....
[][][]..  ..[][][]  ..[]....  ..[]....
..()[]..  ..[]()..  [][][]..  [][][]..

A         B         A         B

....[][]  ....[][]  ..()[]..  ..()[]..
....[]..  ......[]  ..[][]..  ....[][]
..()[]..  ....()[]  ....[]..  ....[]..


thus, under symmetric situations, if the original position is blocked and both L/R kicks work, it will look UGLY...

the next exception for JL may be for situations when only "climbing over" kick is available..

Code:
....()  ()....
[][][]  [][][]
..()[]  []()..
A       B
works

so designer seems to block the rotations where original position is blocked, and both 2 kicks are valid. and they wants to allow kicking if only one of L/R is valid...

but they forgot lots of other situations, such as..

Code:
()()()[][]..
()..()[]....
()....[].... A, and its symmetrical situation

[][]..
[]....
[]().. B, and its symmetrical situation

....()()()
....()..()
[][]....()
..[][]()() and its symmetrical situation,
seems this one happens rarely..


so..

any other idea about why it's designed?

sorry for yingelishir (well it's chinglish)

3. ### Kitaru

It really only has to do with "center-column" blocks of the piece to avoid climbing/"going through" obstacles to reach the opposite side of the stack. The exceptions are if it checks the non-center block first, which can cause a wallkick before it is determined that there is another block that breaks the rule.

4. ### K

your following examples don't work at all in ARS
because, if a block is present on bottom and/or top position, it will not rotate at all.
Code:
..()....
[][][]..
..()[]..

You dig up those extra rules conditions specifics to L/J but honestly they are completely useless.
Gameplay design is harsh, i felt the same frustration long time ago when i implemented ARS into clone.
the possible situation for each piece with working (or not) symmetry is the consequence of the very simple ARS wall-kick system (default/right/left) and NOT the opposite.
whoever dude at ARIKA bended the wall-kick system for allowing those extra L/J situation, it can indicate 2 possibilities :
- they didn't know about all the situation possibilities.
- they deliberately decided to let it that way on purpose
perfection is neither in ARS, nor SRS. It just depend about of how you appropriate it yourself. some people feel it's limitated whereas it can be good to restrict the set to minimum.
I remember people asking long time ago, why the wall-kick system was only 1 block side test and not 2 or 3. We could discuss hours about even it was already discussed but it lead to a damn HenkRogers Point (like godwin one).

oups

5. ### farter

yes i just mean.. if they are also kicked with the 0-R-L order but not blocked by this additional rule, it'll look bad, so they wanna forbid them. lol

now i'm still always blocked by them haha
so every time i failed to rotate J&L, i turn to play xrs and climb~ flip~

6. ### Zaphod77Resident Misinformer

The rule for ARS is simple.

When checking for overlap, it starts checking from the upper left, and going right.

If it finds a center column blocked, it refuses the wallkick, on the grounds that it doesn't know which way it should kick.

However if it finds an overlap in a column that's not the center, it decides that wallkicking is allowed.

The only case where both can happen is the single case with L or J, with box 8 filled, and box 1 or 3 filled. in no other case is it possible for both condition to happen at the same time, and wallkicks to be possible. In this case, because the check is from top down, blocking box 1 or 3 overrides blocking box 8.