Performs the current action (B5D8) with the current target ($B5D9) and instrument (B5DA). During a dry run ($B5EB = 0) nothing is printed or changed, and the routines report success in B5EC instead.

First the basic checks: the action must make sense (9A9F: you cannot, for instance, give something to yourself; if it fails, 'I cannot do that.'). If it is dark (954D) and the action needs light, 'I see nothing.' unless the objects are being carried. The records of the target and instrument are found and saved in B5F8 and $B5FA, and each must be within reach (9686).

Then the handlers are found. If the target (or, for certain actions listed at A13B, the instrument) has handlers of its own for this action (9ADC), they are called one after another: the matching entry and any entries with action 0 straight after it. Otherwise the default handler for the action is looked up in C61F. If there is none, 'I cannot do that.'

Finally, if the action really happened and the player did it in the dark, the darkness message is printed, and 953F gives any character involved as target or instrument a chance to react (99FB).