Humour in games tends to come in two varieties, spontaneous, created by the players, and GM created.
More often than not, the second version falls flat on its face.
Setting out with the intention of making something humourous is extremely difficult. I guess that is why most people are not comedians.
PLayer created humour is frequently triggered by failures at inopportune times. Delivering your heroic speech to inspire your fellows, then fumbling your sword and throwing it across the floor has been the cause for much humour on more than one occaision.
I think the problem with GM created humour is that it frequently requires failure. If you set the characters up to fail, the players are unlikely to find it amusing, if you set the foes up to fail, you are almost robbing the characters of a victory.
I had a NPC once. He was a pompous and overbearing aristocrat. He was very loud and called everyone ‘boy’. He would never go over to talk to someone, if he could just shout and point and get their attention. In the beginning it was amusing. In a later scenario when the characters were trying to lay low, it was challenging. Did it wear thing? I certainly think it did.
I have a game currently on hiatus. The characters are involved with a serial killer and in a set a thief to catch a thief situation. The serial killer is killing killers that have escaped justice. To catch the killer the characters have busted a killer our of jail, hoping that the serial killer will try and get to the guy they are holding, and then they can get the jump on the serial killer and get the job done.
Not only is this a half baked plan anyway, but there was a flaw in the execution (literally) in that the characters went though with the prison break but grabbed the wrong prisoner.
Now, I can see the humour in this. I am not sure the players will.
So what about humour in solo play?
I rarely ever play solo games for actual humour. I have gotten myself into a great many amusing situations. When I was playing Castles & Crusades, Hanson my Paladin was being slowly tracked down by a polar bear. Every time I tried to put some distance between myself and the bear something would come up to hamper me.
In the end, and I do mean the end, I had enough Exp to level up, but no opportunity to do so. Hanson died on a bitterly cold tundra and was eaten by a hungry bear. That is not exactly humour, although some would argue that it is the best use for a paladin, but there was a real sense of the gods laughing on Hanson’s every effort to get away.
Even now, when I look back on his short career it raises a smile.
last week was all about Tales from the Loop, that had real moments of humour, but it is not the focus of the game. It actually leans more towards horror than humour, which is why characters become scared and upset.
So I think that humour has to be spontaneous or it will tend to fall a bit flat. It is not something I play for.