Simple Macro but i don't get it

First sorry i'am not native english writer so.... I actualy run a Game base on the League of legend Univers and it been almost a year since i didnt touch macro , and i can't understand how to make condition in macros in algorithm here what I wanna do. If 1d100<=50    then 1d(player stat)+(weapon stat)(how can i make the player select his weapon ?) else "Player fail his action" I have more question tho , how can i make player select a monster and make the damage output "Real" That it my post is maybe common (i don't realy know) but I hope you can help me :) also i don't wanna copy a template i wanna understand and learn.

Sadly, you can't use if/then type logic within macros without using a script(Pro level option) like PowerCards.  You can make both rolls (attack and damage) and make a "visual" interpretation; IF the attack roll was successful, THEN apply the damage rolled, ELSE ignore the damage.  You can use a query in your macros that allow user input or present multiple selections. ie  @{selected|<attribute's name>}+?{weapon stat?|0}  Presenting a selection for the weapon stat within a macro would be much more complicated based on how the sheet handles numerous weapons.  Someone more familiar with the sheet might have to give an example...   In regards to applying "Real" damage to a monster/opponent;   Macros do not have  write  access to attributes.  T his would only be possible using an API script like TokenMod, ChatSetAttr, etc.

Thanks. that what I wanted to know