You can count headers and I'm still under 20. But that 80 character count per line is bogus.

Well somebody was interested in more 3D stuff, so I stuffed a crude voxel terrain engine into ~16 lines of code (actually ~15 if you get rid of the constant string definition on line 2 or perhaps 14 if you also get rid of lmap_c[][] and just use the map bitmap). Not really a game, but perhaps of some interest; you still have ~5 lines left to make a game out of it.;)

Same usual stuff: Only one semicolon or bracket {} per line, discounting the semicolons inside a for() expression. No commas except for variable definition and lists of parameter arguments in functions.

The engine is set for 32 bit color, which you can change to 15/16/24 bit. Arrow keys to move around. You can also try changing the voxel resolution setting from 3 to 0 to 7. And no optimizations (mostly due to trying to stuff the code), so it may be a bit slow.

You need to create a 512x512 grayscale bitmap (.bmp). Or you can copy the one below, and resave it as a bmp.

http://www.geocities.com/sichoy/map.jpg

[edit] I forgot to get rid of another line, so it's now 14 or 15 lines, depending on whether you keep the mapfile string.

This is a little piece of a rpg.. the battle between the forces of good rabbits and evil rabbits. Who will win? (designed to be like a final fantasy like battle)

[edit added srand(NULL);]

#include <allegro.h>
#include <string.h>
#include <stdlib.h>
/*01*/BITMAP *draw_char(BITMAP *buffer,int x,int y,int half_w,int half_h,int facing) {int gen[32]={half_w,0,half_w/4,-half_h/4,half_w/8,-half_h/2,half_w/8,-half_h*3/4,half_w/4,-half_h*3/4,half_w/2,-half_h/4,half_w*3/4,-half_h/4,half_w*3/4,-half_h/2,half_w,-half_h/2,half_w,-half_h*3/4,half_w/4,half_h/4,half_w/2,half_h*3/4,half_w,half_h*3/4,half_w,half_h,half_w/4,half_h,0,half_h/2},side1[32]={x+gen[0],y+gen[1],x+gen[2],y+gen[3],x+gen[4],y+gen[5],x+gen[6],y+gen[7],x+gen[8],y+gen[9],x+gen[10],y+gen[11],x+gen[12],y+gen[13],x+gen[14],y+gen[15],x+gen[16],y+gen[17],x+gen[18],y+gen[19],x+gen[20],y+gen[21],x+gen[22],y+gen[23],x+gen[24],y+gen[25],x+gen[26],y+gen[27],x+gen[28],y+gen[29],x+gen[30],y+gen[31]},side2[32]={x-gen[0],y+gen[1],x-gen[2],y+gen[3],x-gen[4],y+gen[5],x-gen[6],y+gen[7],x-gen[8],y+gen[9],x-gen[10],y+gen[11],x-gen[12],y+gen[13],x-gen[14],y+gen[15],x-gen[16],y+gen[17],x-gen[18],y+gen[19],x-gen[20],y+gen[21],x-gen[22],y+gen[23],x-gen[24],y+gen[25],x-gen[26],y+gen[27],x-gen[28],y+gen[29],x-gen[30],y+gen[31]};
/*02*/(facing)?polygon(buffer,16,side1,makecol(255,0,0)):polygon(buffer,16,side2,makecol(0,0,255));
/*03*/return buffer;
/*04*/} void main() {BITMAP game_state={/*int 7*/0,(allegro_init()||install_timer()||install_keyboard()||set_gfx_mode(GFX_AUTODETECT_WINDOWED,320,200,0,0))?-1:50,text_mode(-1),40,100,80,100,/*pointers 4*/NULL,NULL,NULL,NULL,/*long int*/0,/*pointer*/NULL,/*int 3*/270,130,0},game_state2={/*int 7*/5,10,0,0,0,0,0,/*pointers 4*/NULL,NULL,NULL,NULL,/*long int*/0,/*pointer*/NULL,/*int 3*/0,0,0},*buffer=create_bitmap(320,200);
/*05*/srand(time(NULL));
/*06*/while((game_state.cr>0||game_state.ct>0)&&memset(buffer->dat,0,320*200)&&game_state.h>0&&!key[KEY_DOWN]|(game_state.w=0)) while(game_state.w++<12)(game_state.w==1) ? textprintf(buffer,font,10,10,makecol(0,255,0),"Push [left] for magic"):(game_state.w==2) ? textprintf(buffer,font,10,20,makecol(0,255,0),"Push [up] for attack"):(game_state.w==3)?textprintf(buffer,font,10,30,makecol(0,255,0),"Push [Down] to Run"):(game_state.w==4)?((key[KEY_UP]&&game_state.seg==0&&game_state.ct>0)? game_state.seg=30*(game_state.id=1) : (key[KEY_LEFT]&&game_state.seg==0&&game_state.cr>0)? game_state.seg=15*(game_state.id=2) : (game_state.seg>0)? rest(game_state.seg--): (game_state.id==4)? game_state.id=(game_state.h-=(rand())%20) : (game_state.id==1)?(game_state.id=((game_state2.w-=(1+rand()%3))>0)?0*(game_state.seg=25)+4:(game_state.ct=-30)):(game_state.id==2)?(game_state.id=((game_state2.h-=(1+rand()%3))>0)?(game_state.seg=25)*0+4:(game_state.cr=-30)):rest(1)):(game_state.w==5)?((game_state.id==1)? line(buffer,game_state.ct+game_state.seg,game_state.cb+game_state.seg,game_state.ct+game_state.seg+20,game_state.cb+game_state.seg+20,makecol(255,200,200)): rest(1)):(game_state.w==6)?((game_state.id==2)?circle(buffer,game_state.cl,game_state.cr,game_state.seg,makecol(255,255,255)):rest(1)):(game_state.w==7)?(void)draw_char(draw_char(draw_char(buffer,game_state.ct,game_state.cb,20,20,TRUE),game_state.cl,game_state.cr,20,20,TRUE),game_state.x_ofs,game_state.y_ofs,20,20,FALSE):(game_state.w==8)?line(buffer,game_state.x_ofs-33,game_state.y_ofs+23,game_state.x_ofs-33+game_state.h,game_state.y_ofs+23,makecol(0,255,0)):(game_state.w==9)?line(buffer,game_state.ct+13,game_state.cb+23,game_state.ct+13+game_state2.w,game_state.cb+23,makecol(0,255,0)):(game_state.w==10)?line(buffer,game_state.cl+13,game_state.cr+23,game_state.cl+13+game_state2.h,game_state.cr+23,makecol(0,255,0)):(game_state.w==11)?(game_state.id==4)?line(buffer,game_state.x_ofs-20+game_state.seg,game_state.y_ofs+game_state.seg,game_state.x_ofs+game_state.seg,game_state.y_ofs+game_state.seg+20,makecol(255,200,200)):rest(1):blit(buffer,screen,0,0,0,0,320,200); 
/*07*/while(!key[KEY_ESC])(game_state.cr<0&&game_state.ct<0)? (textprintf_centre(screen,font,160,100,makecol(0,255,0),"You win! Push [Esc] to quit")):(textprintf_centre(screen,font,160,100,makecol(0,255,0),"You lose! Push [Esc] to quit"));
} END_OF_MAIN()

hehe well it depends on your compiler..
since I forgot to use srand(time(NULL)); you will either win or lose depending on the sequence of number generated by rand()...

on my computer I win.. so.. hmm anyway its easy enough to add a srand(time(NULL)); with out pushing it past the limit.

You do know what the word funny means, right? And that think is spelled with a k?

Sorry 'bout that but I just had to...

BTW, I thought that whole funny business was a German thing or something...

Just to complete the collection of 20 line interpretations of classic games, here's Pacman:

I think I followed the "rules". If not, fsck it.

Ooh, casting function pointers to get around the void return values... not portable I almost used raise(SIGABRT), which returns int, in my game, but in the end I didn't need it.

One or two bugs(?) in the game, namely that the whole background goes yellow whenever his mouth is closed, and the thingy doesn't stop moving when I let go of the keys (I wish he would). Otherwise works well

Well, I just joined {allegro.cc} tonight. I've been reading the forums for a while and decided it was time I gave my two cents, or in this case, my twenty lines. here goes...

It is a top view car racing game. No opponent, just a time trial though. Figur eights around the two circles. I hope you enjoy

I couldnt get pacman to compile at all...
compiler says 3 times on line 4 too many arguments to function -- maybe i have an old version of allegro or gcc.....

This is the first thread that I've read on allegro.cc in about a week or two and I decided to try to do the challenge, It's not an rpg but its tile based...... I did some things that may be considered cheap and cheating but I kept my code under 20 lines (19 I think) and no line has more than one semi colon on it.... the actual .cpp file is just under 5kb....

if there is word wrap on here it might not be under 20 lines on here, but the .cpp file i have is under 20 with no more than 1 semicolon per line.....

anyways its a remake of an old game that I made (first game I ever made) on my b&w trs-80 model 4 computer with basic.....(it was in textmode)

Bricks & Money "fall", if you walk on the money -- you get a point and it disappears, if you walk on the bricks you die, esc quits, dont hold keys down -- tap them (sorry bout this, its hard to do good keyboard routines in a couple of lines -- for me anyways) It gets interesting once you're score is about 200 - 300, which is a while to wait...

by the way I lied about my game -- the line with the for loop has two semicolons I think...

oh cool no warnings this time... thanks BP! -- but it's tilebased -- since when is pacman tilebased?
And no fruit and when you beat it -- nothing happens and only one life -- heh sorry I'm a big pac-man fan.....(nitpick nitpick nitpick) but it should almost go without saying -- great job!

since forever! -- the walls are always thin and the pathways wide -- if you can call that tilebased, maybe it is, but I dont see how at this point....

Pac-Man is soooo tile-based! Not terribly attractive tiles, but tiles all the same.

BTW, this thread is a good example of why we need pages in the forums. How's that coming, Matthew?

The original pacman:
http://roms2.mame.dk/png/puckman.png
Take a look at the rom, check the gfx set, and you'll see the individual tiles

Edit:
You can see the individual tiles, if you take a look at the IBM PC character set
Edit2:
http://web-wise-wizard.com/web-lookup-lists/dem/ascii-ibm/ascii_12.gif