There are some weird characters that you will meet in Baldur's Gate 3, and many of them are a little scary as well. Oliver is a Tiefling child who you will meet as you approach the end of Act One, living in the Ruined Battlefield area. He lives in the "House with Flowers" and will ask you to play a game of Hide and Seek with him.
Unfortunately, you will have to play with him, as turning the offer down will anger him and cause him to send his "family" after you, which is a difficult fight. Luckily, finding him isn't too hard of a task once you know what to do and when to do it.
Updated by Shane Black on August 25, 2023: This guide was updated to give more details on the mechanics of Oliver’s family and how they move around the map, while also giving a new clue on how you can track Oliver’s movements while he is invisible in the second phase of the game. Also added more links to relevant guides.
Beat Oliver At Hide And Seek
The game will be split into two rounds, with the first round being fairly simple. Oliver will begin the game by turning himself invisible and going to hide, which sounds like cheating, but whatever. You will then have to find him, and this can easily be done by following the word "Invisible" as Oliver leaves the house to hide.
If you lose track of the word, don't worry: he is hiding behind the cart outside the house. Just send a party member outside and to the cart, and then have them pass a Perception Check to find him and end the first round of the game.
Oliver will be upset that you found him and challenge you to the second round of the game, but this time, you will have to avoid his "family" members as well in order to win the game. If any of these members find you, you will then have to go into a difficult battle with them.
You will need to look out for the shadows that are all over the map as well, as the family members can use them to quickly move around the area. They can warp to a shadow, deal some damage to you, and then leave really quickly if you enter combat with them. Because of this, keep your party members as far away from them as possible.
This round will also be in the turn-based mode, so you can see what the members of the family are doing. But, once again, there is a simple trick to winning this round that will ensure your victory. The trick is to have three of your party members stay in the house, crouched and hiding in a corner to avoid being detected. This will keep them out of the way.
Next, with the one character you choose to find Oliver with, send them to the spot where you first met Oliver. You see, after one round of turns, Oliver will begin moving to different spots around the area, eventually coming to this spot again. If you put your character here and have them hide to avoid detection, he will eventually make his way next to you where you can pop out of sneaking and get him.
You can also keep an eye out for the small magical orbs that float around Oliver while he is invisible to track his movement. These can be a little tricky to see among everything else happening on the screen, but if you manage to spot them, then can be handy to see where he is at all times. However, the method of hiding at the one spot until he comes to you is still the advised method.
Of course, Oliver will still be upset like the bratty kid that he is, but he won't make you play anymore and follow through on his promise of a prize. This prize is the Ring of Shadows, which will let the wearer cast Pass Without Trace once per day, as well as a +10 bonus to Stealth Checks. Not a bad haul for a simple game with a child.