100 Merc resources for MUD players

Add -fcommon to your CFLAGS in the Makefile to resolve multiple definition errors caused by global variables in merc.h.

Modern Linux distributions require linking against libcrypt explicitly; ensure -lcrypt is appended to the L_FLAGS line in your Makefile.

Replace deprecated bzero() calls with memset() and bcopy() with memmove() to comply with POSIX standards and avoid compiler warnings.

Update signal handler functions in comm.c to match the expected 'void function(int)' signature to prevent segmentation faults during signal traps.

Audit sprintf calls in act_wiz.c and comm.c, replacing them with snprintf to prevent buffer overflows, a common vulnerability in Merc derivatives.

Ensure all time-related variables use the time_t type rather than int to avoid 32-bit integer overflow issues on modern 64-bit systems.

Update memory allocation in db.c to use calloc() for automatic zero-initialization of structs, reducing 'garbage data' bugs in new mobile instances.

Replace the blocking gethostbyname() in comm.c with getaddrinfo() to support IPv6 and improve DNS resolution reliability.

Remove the 'inline' keyword from function definitions in handler.c if using older C standards that treat it as a linkage error.

Cast return values of alloc_perm and alloc_mem to the specific struct pointer type to satisfy stricter type checking in modern GCC versions.

Maintain a master spreadsheet of Virtual Number (VNUM) ranges to prevent collisions between original Merc areas and custom additions.

Ensure every .are file ends with the specific '#$' string; failure to include this will cause the boot_db() function to hang or crash.

Assign spec_fun pointers in special.c to mobile VNUMs to enable unique behaviors like breath weapons or spellcasting.

Master the 'M P G E' reset codes: M (Mobile), P (Put in container), G (Give to mob), E (Equip on mob) for population logic.

Set sector types correctly in the #ROOMS section; SECT_INSIDE and SECT_CITY affect movement point cost and light requirements.

Utilize the 'E' flag in objects and rooms to provide 'look' targets for items that are not separate objects, saving VNUM space.

Configure exit states: 0 (Open), 1 (Is Door), 2 (Pickproof Door) to control player navigation and thief skill utility.

Adjust the two integer values in the #SHOPS section to set the buy/sell markup; standard Merc values are 120 (buy) and 90 (sell).

Always register new .are files in the area.lst file in the /area directory; the engine will not load files not explicitly listed here.

Use automated Perl scripts to add the 'Resist' and 'Affect' bitvectors required if porting legacy Merc areas to the ROM 2.4 codebase.

Understand the 'char_next = ch->next; ... ch = char_next;' pattern in update.c to safely extract or kill mobs during loop iterations.

Analyze the main game loop in comm.c to understand how non-blocking I/O handles multiple concurrent telnet connections.

Modify the formula in gain_exp() within fight.c to adjust the leveling speed and prevent power-leveling via high-VNUM mob kills.

Check the apply_ac() and can_carry_w() functions to debug issues where players become encumbered or lose AC benefits.

Use 'gdb src/merc area/core' to identify the specific line in handler.c or fight.c that caused a crash during combat.

Control combat pacing by adjusting the WAIT_STATE macro values for skills like bash, kick, or spellcasting.

Examine save.c to understand the keyword-based PFILE format; ensure the 'End' tag is written correctly to prevent character corruption.

Register new skill names in the skill_table within const.c and define the corresponding spell_ or do_ function in magic.c or interp.c.

Order the command table alphabetically or by power level to ensure 'north' is parsed before custom commands starting with 'n'.

Implement a basic recycle.c system to reuse freed memory chunks, reducing the overall memory footprint of long-running Merc instances.